py-curl: updated to 7.43.0.1

Version 7.43.0.1:
* WRITEHEADER/WRITEFUNCTION and WRITEDATA/WRITEFUNCTION can now
  be set on the same handle. The last call will take precedence over
  previous calls. Previously some combinations were not allowed.
* Fixed a crash when using WRITEDATA with a file-like object followed
  by WRITEDATA with a real file object.
* Fixed a theoretical memory leak in module initialization.
* Added support for CURL_SSLVERSION_MAX_* constants.
* Added support for CURLSSH_AUTH_AGENT.
* Added support for CURLOPT_CONNECT_TO.
* Added support for CURLINFO_HTTP_VERSION.
* Fixed build against OpenSSL l.1 on Windows.
* Added set_ca_certs method to the Easy object to set CA certificates
  from a string.
* Python 3.6 is now officially supported.
* Added support for CURLOPT_PROXY_CAPATH.
* C-Ares updated to 1.12.0 in Windows builds, fixing DNS resolution
  issues on Windows.
* Added --openssl-lib-name="" option to support building against
  OpenSSL 1.1.0 on Windows.
* Fixed a possible double free situation in all Curl objects
  due to a misuse of the trashcan API.
* High level Curl objects can now be reused.
* LARGE options fixed under Windows and Python 3 (INFILESIZE,
  MAX_RECV_SPEED_LARGE, MAX_SEND_SPEED_LARGE, MAXFILESIZE,
  POSTFILESIZE, RESUME_FROM).
* Fixed compilation on Solaris.
* ENCODING option can now be unset

(adam)