Cleaning up/fix proxy/Host: header logic. Working to do the same

for apache-2.0 where we also have an ascii [num] representation of
IPv6's to take into account which currently only takes the non
proxy situation into account.

PR:
Obtained from:
Submitted by:
Reviewed by:


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@89230 13f79535-47bb-0310-9956-ffa450edef68