Merge r529626 from trunk:

log the uri for some access-denied paths when r->filename is
unset

Submitted by: trawick
Reviewed by: trawick, rpluem, covener


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@614663 13f79535-47bb-0310-9956-ffa450edef68