Merge r639465 from trunk:

* Initialize hash needed by ap_register_rewrite_mapfunc early enough.

PR: 44641
Submitted by: Daniel Lescohier <daniel.lescohier cnet.com>
Reviewed by: rpluem, niq, wrowe, jim

Submitted by: rpluem
Reviewed by: rpluem, niq, trawick


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@660572 13f79535-47bb-0310-9956-ffa450edef68