curl: Update to 7.68.0

pkgsrc changes:
 - Removes patch-configure hunks applied upstream

Changes:
7.68.0
------
This release includes the following changes:

 o TLS: add BearSSL vtls implementation
 o XFERINFOFUNCTION: support CURL_PROGRESSFUNC_CONTINUE
 o curl: add --etag-compare and --etag-save
 o curl: add --parallel-immediate
 o multi: add curl_multi_wakeup()
 o openssl: CURLSSLOPT_NO_PARTIALCHAIN can disable partial cert chains

This release includes the following bugfixes:

 o CVE-2019-15601: file: on Windows, refuse paths that start with \\
 o Azure Pipelines: add several builds
 o CMake: add support for building with the NSS vtls backend
 o CURL-DISABLE: initial docs for the CURL_DISABLE_* defines
 o CURLOPT_HEADERFUNCTION.3: Document that size is always 1
 o CURLOPT_QUOTE.3: fix typos
 o CURLOPT_READFUNCTION.3: fix the example
 o CURLOPT_URL.3: "curl supports SMB version 1 (only)"
 o CURLOPT_VERBOSE.3: see also ERRORBUFFER
 o HISTORY: added cmake, HTTP/3 and parallel downloads with curl
 o HISTORY: the SMB(S) support landed in 2014
 o INSTALL.md: provide Android build instructions
 o KNOWN_BUGS: Connection information when using TCP Fast Open
 o KNOWN_BUGS: LDAP on Windows doesn't work correctly
 o KNOWN_BUGS: TLS session cache doesn't work with TFO
 o OPENSOCKETFUNCTION.3: correct the purpose description
 o TrackMemory tests: always remove CR before LF
 o altsvc: bump to h3-24
 o altsvc: make the save function ignore NULL filenames
 o build: Disable Visual Studio warning "conditional expression is constant"
 o build: fix for CURL_DISABLE_DOH
 o checksrc.bat: Add a check for vquic and vssh directories
 o checksrc: repair the copyrightyear check
 o cirrus-ci: enable clang sanitizers on freebsd 13
 o cirrus: Drop the FreeBSD 10.4 build
 o config-win32: cpu-machine-OS for Windows on ARM
 o configure: avoid unportable `==' test(1) operator
 o configure: enable IPv6 support without `getaddrinfo`
 o configure: fix typo in help text
 o conncache: CONNECT_ONLY connections assumed always in-use
 o conncache: fix multi-thread use of shared connection cache
 o copyrights: fix copyright year range
 o create_conn: prefer multiplexing to using new connections
 o curl -w: handle a blank input file correctly
 o curl.h: add two missing defines for "pre ISO C" compilers
 o curl/parseconfig: fix mem-leak
 o curl/parseconfig: use curl_free() to free memory allocated by libcurl
 o curl: cleanup multi handle on failure
 o curl: fix --upload-file . hangs if delay in STDIN
 o curl: fix -T globbing
 o curl: improved cleanup in upload error path
 o curl: make a few char pointers point to const char instead
 o curl: properly free mimepost data
 o curl: show better error message when no homedir is found
 o curl: show error for --http3 if libcurl lacks support
 o curl_setup_once: consistently use WHILE_FALSE in macros
 o define: remove HAVE_ENGINE_LOAD_BUILTIN_ENGINES, not used anymore
 o docs: Change 'experiemental' to 'experimental'
 o docs: TLS SRP doesn't work with TLS 1.3
 o docs: fix several typos
 o docs: mention CURL_MAX_INPUT_LENGTH restrictions
 o doh: improved both encoding and decoding
 o doh: make it behave when built without proxy support
 o examples/postinmemory.c: Call curl_global_cleanup always
 o examples/url2file.c: corrected erroneous comment
 o examples: add multi-poll.c
 o global_init: undo the "intialized" bump in case of failure
 o hostip: suppress compiler warning
 o http_ntlm: Remove duplicate NSS initialisation
 o lib: Move lib/ssh.h -> lib/vssh/ssh.h
 o lib: fix compiler warnings with `CURL_DISABLE_VERBOSE_STRINGS`
 o lib: fix warnings found when porting to NuttX
 o lib: remove ASSIGNWITHINCONDITION exceptions, use our code style
 o lib: remove erroneous +x file permission on some c files
 o libssh2: add support for ECDSA and ed25519 knownhost keys
 o multi.h: remove INITIAL_MAX_CONCURRENT_STREAMS from public header
 o multi: free sockhash on OOM
 o multi_poll: avoid busy-loop when called without easy handles attached
 o ngtcp2: Support the latest update key callback type
 o ngtcp2: fix thread-safety bug in error-handling
 o ngtcp2: free used resources on disconnect
 o ngtcp2: handle key updates as ngtcp2 master branch tells us
 o ngtcp2: increase QUIC window size when data is consumed
 o ngtcp2: use overflow buffer for extra HTTP/3 data
 o ntlm: USE_WIN32_CRYPTO check removed to get USE_NTLM2SESSION set
 o ntlm_wb: fix double-free in OOM
 o openssl: Revert to less sensitivity for SYSCALL errors
 o openssl: improve error message for SYSCALL during connect
 o openssl: prevent recursive function calls from ctx callbacks
 o openssl: retrieve reported LibreSSL version at runtime
 o openssl: set X509_V_FLAG_PARTIAL_CHAIN by default
 o parsedate: offer a getdate_capped() alternative
 o pause: avoid updating socket if done was already called
 o projects: Fix Visual Studio projects SSH builds
 o projects: Fix Visual Studio wolfSSL configurations
 o quiche: reject HTTP/3 headers in the wrong order
 o remove_handle: clear expire timers after multi_done()
 o runtests: --repeat=[num] to repeat tests
 o runtests: introduce --shallow to reduce huge torture tests
 o schannel: fix --tls-max for when min is --tlsv1 or default
 o setopt: Fix ALPN / NPN user option when built without HTTP2
 o strerror: Add Curl_winapi_strerror for Win API specific errors
 o strerror: Fix an error looking up some Windows error strings
 o strerror: Fix compiler warning "empty expression"
 o system.h: fix for MCST lcc compiler
 o test/sws: search for "Testno:" header unconditionally if no testno
 o test1175: verify symbols-in-versions and libcurl-errors.3 in sync
 o test1270: a basic -w redirect_url test
 o test1456: remove the use of a fixed local port number
 o test1558: use double slash after file:
 o test1560: require IPv6 for IPv6 aware URL parsing
 o tests/lib1557: fix mem-leak in OOM
 o tests/lib1559: fix mem-leak in OOM
 o tests/lib1591: free memory properly on OOM, in the trailers callback
 o tests/unit1607: fix mem-leak in OOM
 o tests/unit1609: fix mem-leak in OOM
 o tests/unit1620: fix bad free in OOM
 o tests: Change NTLM tests to require SSL
 o tests: Fix bounce requests with truncated writes
 o tests: fix build with `CURL_DISABLE_DOH`
 o tests: fix permissions of ssh keys in WSL
 o tests: make it possible to set executable extensions
 o tests: make sure checksrc runs on header files too
 o tests: set LC_ALL=en_US.UTF-8 instead of blank in several tests
 o tests: use DoH feature for DoH tests
 o tests: use \r\n for log messages in WSL
 o tool_operate: fix mem leak when failed config parse
 o travis: Fix error detection
 o travis: abandon coveralls, it is not reliable
 o travis: build ngtcp2 with --enable-lib-only
 o travis: export the CC/CXX variables when set
 o vtls: make BearSSL possible to set with CURL_SSL_BACKEND
 o winbuild: Define CARES_STATICLIB when WITH_CARES=static
 o winbuild: Document CURL_STATICLIB requirement for static libcurl

This release includes the following known bugs:

 o see docs/KNOWN_BUGS (https://curl.haxx.se/docs/knownbugs.html)


(leot)