Merge r1829513 from trunk:

* modules/ssl/ssl_engine_init.c (ssl_init_Module): Don't enable SSL
  for a vhost if SSLEnable is not used and no certs are configured,
  even if the Listen protocol is "https".  Restores behaviour to that
  prior to r1809303 for configs which would now otherwise fail at
  startup.

Submitted by: jorton
Reviewed by: jorton, jim, ylavic


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1832495 13f79535-47bb-0310-9956-ffa450edef68