Merge r1644503 from trunk

   * mod_proxy_ajp: Fix handling of the default port (8009) in the
     ProxyPass and <Proxy> configurations.  PR 57259.

Submitted by: ylavic
Reviewed by: ylavic, jim, covener
Backported by: jailletc36

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1650655 13f79535-47bb-0310-9956-ffa450edef68