Merge r1706918 from trunk:

m4: please any autoconf by quoting AC_DEFUN's names. PR 58126.

Submitted by: olli hauer <ohauer gmx.de>

Submitted by: ylavic
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1707038 13f79535-47bb-0310-9956-ffa450edef68