Merge r1652930, r1652933 from trunk

   * acinclude.m4: Generate #LoadModule directive in default httpd.conf for
                   every --enable-mpms-shared. PR 53882.

Submitted by: olli hauer <ohauer gmx.de>, Yann Ylavic
Reviewed by: ylavic, rjung, jailletc36
Backported by: jailletc36

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1661848 13f79535-47bb-0310-9956-ffa450edef68