Merge r1505986 from trunk:

not valid in htaccess,  http://httpd.apache.org/docs/2.4/mod/mod_cache.html#comment_1510



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1505987 13f79535-47bb-0310-9956-ffa450edef68