Proxy should not make bogus fqdn:port DNS queries

In proxy 5.6 in order to fix 1000586, we've added the following commit:
commit 4273986e4c1996c6c575a4cc4ca9d2c5587acf1c
Author: Stephen Herr <sherr@redhat.com>
Date:   Fri Aug 23 14:46:32 2013 -0400

    1000586 - /etc/hosts doesn't work with proxies

It does a "socket.gethostbyname(req.headers_in['Host'])", but since RHEL 5
clients over https send 'server.domain:443' host headers, we end up
doing lots of odd queries to the DNS servers (note the :443 at the end):
22:12:00.733856 IP 172.16.11.11.49785 > 172.16.11.254.53: 60115+ A?  satproxy.int.rhx:443.int.rhx. (46)
22:12:00.734481 IP 172.16.11.254.53 > 172.16.11.11.49785: 60115 NXDomain* 0/1/0 (93)

Clients with python2.4 (RHEL5) using a proxy over https set the
Host: header to values like 'server.domain:443'. Python 2.6
clients (RHEL 6) set the Host: header in the form 'server.domain' when
connecting to the same proxy over https. The HTTP rfc (2616) allows
both. This change in Python's HTTPConnection class happened via
6 RFE #1472176.

Fix this by leaving out the ':port' part.

Signed-off-by: Michele Baldessari <michele@acksyn.org>
Automatic commit of package [spacewalk-proxy] release [2.2.1-1].