fix copy/paste error for CacheSocacheMinTime, rest of content is correct.

  http://httpd.apache.org/docs/trunk/mod/mod_cache_socache.html#comment_3247



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1637768 13f79535-47bb-0310-9956-ffa450edef68