Merge r1309585 from trunk:

static scope for rewritemap_mutex_type.

Submitted by: nd
Reviewed by: sf, jorton, trawick


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1333493 13f79535-47bb-0310-9956-ffa450edef68