systemtests python-bareos: prevent warnings

When trying an unsuccessful authentication,
Python issues a warning message about an unclosed SSL socket.
This change hides these warnings.

It also contain a workaround to prevent a Deprecation Warning in Python > 3.2.

python-bareos/bareos/bsock/lowlevel.py

@@ -295,7 +295,7 @@ def _init_connection(self):
 
     def close(self):
         """disconnect"""
-        if self.socket:
+        if self.socket is not None:
             self.socket.close()
         self.socket = None