Log rhn proxy server and proxy port

Since these were not set in the large call to subscription-
manager, they were not logged. Log them.

Change-Id: Ia3c5a58c9b983af6ba0ee7d4eab90ca4e6b5b1eb
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1082519
Signed-off-by: Ryan Barry <rbarry@redhat.com>