Merge r1028797, r1028799 from https://svn.apache.org/repos/asf/httpd/httpd/trunk/:

Add a note about LimitRequest* and name-based vhosts as followup on PR#7741


make the name-based vhost note a warning based on offline discussion with Rich




git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@1028802 13f79535-47bb-0310-9956-ffa450edef68