Update py-borgbackup to 1.1.10.

Note that we do not use the bundled msgpack (see below) in pkgsrc.

Version 1.1.10 (2019-05-16)

Fixes:

  * extract: hang on partial extraction with ssh: repo, when hardlink master is
    not matched/extracted and borg hangs on related slave hardlink, #4350
  * lrucache: regularly remove old FDs, #4427
  * avoid stale filehandle issues, #3265
  * freebsd: make xattr platform code api compatible with linux, #3952
  * use whitelist approach for borg serve, #4097
  * borg command shall terminate with rc 2 for ImportErrors, #4424
  * create: only run stat_simple_attrs() once, this increases backup with lots
    of unchanged files performance by ~ 5%.
  * prune: fix incorrect borg prune --stats output with --dry-run, #4373
  * key export: emit user-friendly error if repo key is exported to a
    directory, #4348

New features:

  * bundle latest supported msgpack-python release (0.5.6), remove
    msgpack-python from setup.py install_requires - by default we use the
    bundled code now. optionally, we still support using an external msgpack
    (see hints in setup.py), but this requires solid requirements management
    within distributions and is not recommended. borgbackup will break if you
    upgrade msgpack to an unsupported version.
  * display msgpack version as part of sysinfo (e.g. in tracebacks)
  * timestamp for borg delete --info added, #4359
  * enable placeholder usage in --comment and --glob-archives, #4559, #4495

Other:

  * serve: do not check python/libc for borg serve, #4483
  * shell completions: borg diff second archive
  * release scripts: signing binaries with Qubes OS support
  * testing:
      + vagrant: upgrade openbsd box to 6.4
      + travis-ci: lock test env to py 3.4 compatible versions, #4343
      + get rid of confusing coverage warning, #2069
      + rename test_mount_hardlinks to test_fuse_mount_hardlinks, so both can
        be excluded by "not test_fuse".
      + pure-py msgpack warning shall not make a lot of tests fail, #4558
  * docs:
      + add "SSH Configuration" section to "borg serve", #3988, #636, #4485
      + README: new URL for funding options
      + add a sample logging.conf in docs/misc, #4380
      + elaborate on append-only mode docs, #3504
      + installation: added Alpine Linux to distribution list, #4415
      + usage.html: only modify window.location when redirecting, #4133
      + add msgpack license to docs/3rd_party/msgpack
  * vagrant / binary builds:
      + use python 3.5.7 for builds
      + use osxfuse 3.8.3

(bsiegert)