Merge r1347998 from trunk:

* configure.in: Enforce 1.4.0 as minimum APR version requirement.

PR: 52748

Submitted by: jorton
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1359688 13f79535-47bb-0310-9956-ffa450edef68