set proper default values to Broker.connect() method

Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1093646
Change-Id: I2e9c7fc850e1a2f1a6293d5c703d977d1b877523
Signed-off-by: Jiri Moskovcak <jmoskovc@redhat.com>