mod_rewrite: Check all files used by DBM maps for freshness, mod_rewrite

didn't pick up on updated sdbm maps due to this.
PR41190 [Niklas Edmundsson]

NOTE: Only tested on httpd-2.2.8.



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@632730 13f79535-47bb-0310-9956-ffa450edef68