Provide new ap_update_child_status_from_conn() mostly

for use with mod_noloris.c Add some logic protection, for
NULL ref, which shoulda be there in any case.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@821307 13f79535-47bb-0310-9956-ffa450edef68