Merge r1467765 from trunk:

Fix crash in mod_log_config when logging
request end time for a failed request
(LogFormat contains %{end}t).

The request_config for mod_log_config might
not be initialized.

PR 54828.

Submitted by: rjung
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1467981 13f79535-47bb-0310-9956-ffa450edef68