Merge r1410681:

   * mod_rewrite: PR53963: Ad an opt-in RewriteOption to control merging of RewriteBase
                  (This merge started happening in 2.4.0/2.2.23)

Submitted by: covener
Reviewed by: covener, minfrin, sf



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1418954 13f79535-47bb-0310-9956-ffa450edef68