sound_canberra pylint fixes

Author: lakshyacis

src/plugins/sound_canberra.py

@@ -1,4 +1,8 @@
 # -*- coding: utf-8 -*-
+"""
+src/plugins/proxyconfig_stem.py
+===================================
+"""
 
 from pybitmessage.bitmessageqt import sound
 
@@ -14,7 +18,8 @@
 }
 
 
-def connect_plugin(category, label=None):
+def connect_plugin(category, label=None):    # pylint: disable=unused-argument
+    """Method helps to connect with plugin"""
     try:
         _canberra.play(0, pycanberra.CA_PROP_EVENT_ID, _theme[category], None)
     except (KeyError, pycanberra.CanberraException):