Add SSL_COMPRESS_METHOD variable (included in +StdEnvVars) to note
  the negotiated compression.

Reviewed by: wrowe, Maxime Petazzoni
Submitted by: Georg v. Zezschwitz <gvz 2scale.de>


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@209469 13f79535-47bb-0310-9956-ffa450edef68