Merge r1392347 from trunk:

core: ErrorDocument now works for requests without a Host header.

PR: 48357

Submitted by: trawick
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1394035 13f79535-47bb-0310-9956-ffa450edef68