Merge r1808780 from trunk:

mod_speling/PR 38923: don't embed Referer in link in error page.

Submitted by: niq
Reviewed by: niq, ylavic, elukey


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1808856 13f79535-47bb-0310-9956-ffa450edef68