Merge r1831773 from trunk:

PR62311: only create the rewritelock when needed

Submitted By: Hank Ibell <hwibell gmail.com>
Committed By: covener



Submitted by: covener
Reviewed by: jailletc36, icing (by inspection), covener


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1848681 13f79535-47bb-0310-9956-ffa450edef68