Ensure that we always return a FQDN... This is not guaranteed by either

apr_sockaddr_info_get() or apr_getnameinfo(). Also note that under
OS X, apr_getnameinfo() always seems to fail (at least on my
machines) so if we don't specific ServerName at the global setting,
we get a warning.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@164092 13f79535-47bb-0310-9956-ffa450edef68