Merge r1393058 from trunk:

mod_include: When an include file or virtual path fails, include the result
code that tells us why.

Submitted by: minfrin
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1394027 13f79535-47bb-0310-9956-ffa450edef68