Merge branch 'jk/curl-avoid-deprecated-api' into maint-2.39

Deal with a few deprecation warning from cURL library.

* jk/curl-avoid-deprecated-api:
  http: support CURLOPT_PROTOCOLS_STR
  http: prefer CURLOPT_SEEKFUNCTION to CURLOPT_IOCTLFUNCTION
  http-push: prefer CURLOPT_UPLOAD to CURLOPT_PUT

Author: gitster