Support for OpenSSL 1.1.0:

- ab: use new API SSL_CTX_set_max_proto_version()
  and SSL_CTX_set_min_proto_version() in
  combination with TLS_client_method() instead
  of the old deprecated methods.

Backport of r1735891 from trunk.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x-openssl-1.1.0-compat@1755851 13f79535-47bb-0310-9956-ffa450edef68