merge r1608284 from trunk:

The SNI callback already logs a debug message when the vhost
is found or no vhost matches.  Log one when no name is provided
by the client.

Submitted by: trawick
Reviewed by: covener, minfrin


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1610010 13f79535-47bb-0310-9956-ffa450edef68