"Listen 80" just works now, using v4-only, v6-only, mapped address

or non-mapped address.

Submitted by:	Colm MacCarthaigh <colm@stdlib.net>


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@101337 13f79535-47bb-0310-9956-ffa450edef68