Merge r377291 from trunk:

Make the worker and event MPMs support GracefulShutdownTimeout just like
the prefork MPM does.

Submitted by: Chris Darroch <chrisd pearsoncmg.com>
Ported to event MPM by: rooneg
Issue number: 38621

* server/mpm/worker/worker.c
  (ap_mpm_run): Make the graceful shutdown log message refer to the right
   signal, and respect the graceful shutdown timeout if there is one.

* server/mpm/experimental/event/event.c
  (ap_mpm_run): Ditto.

* CHANGES: Note change.

Submitted by: chrisd, rooneg
Reviewed by: chrisd, rpluem, trawick
PR: 38621


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@410935 13f79535-47bb-0310-9956-ffa450edef68