proxy_cache.c was still in the ApacheModuleProxy project, although that

modules is deprecated.  Remove it from the project.
Submitted by:	Bill Rowe <wrowe@apache.org>


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@86096 13f79535-47bb-0310-9956-ffa450edef68