Add {transcode_key} and {username} notification options

plexpy/notifiers.py

@@ -1884,7 +1884,7 @@ class Scripts(object):
                   script_args(list): ["python2", '-p', '-zomg']
         """
         logger.debug(u"PlexPy Notifiers :: Trying to run notify script, action: %s, arguments: %s" %
-                     (notify_action if notify_action else None, script_args if script_args else None))
+                     (notify_action or None, script_args or None))
 
         if script_args is None:
             script_args = []