mod_proxy_http: Use the same hostname for SNI as for the HTTP request when

forwarding to SSL backends.

PR: 53134
Backports: r1333969
Submitted by: Michael Weiser <michael weiser.dinsnail.net>, rpluem
Reviewed by: covener, wrowe, rjung



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@1497470 13f79535-47bb-0310-9956-ffa450edef68