Don't cache requests with a expires date in the past; otherwise mod_cache will

always try to cache the URL. This bug might lead to numerous rename() errors
on win32 if the URL was previously cached.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@450055 13f79535-47bb-0310-9956-ffa450edef68