Merge r1302674:

  Revert r1299786, which is already covered elsewhere in the same document:
    document that ap_mpm_query is available only after register hooks
    PR: 52889


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1302678 13f79535-47bb-0310-9956-ffa450edef68