[irc] Don't reply to server NOTICEs

[Stefano Rivera]

INFO source.freenode: Signed on
DEBUG core.dispatcher: {'account': None, 'responses': [], 'source': u'freenode', 'processed': False, 'time': 1246887557.5836799, 'identity': 2, 'message': {'raw': u'*** No identd (auth) response', 'deaddressed': u'*** No identd (auth) response', 'clean': u'*** No identd (auth) response', 'stripped': u'*** No identd (auth) response'}, 'type': u'notice', 'public': True, 'channel': u'AUTH', 'sender': {'nick': u'', 'connection': u'', 'id': u''}}
DEBUG source.freenode: Received notice from in testibid: *** Your host is holmes.freenode.net[shakermaker.preshweb.co.uk/6667], running version hyperion-1.0.2b
DEBUG core.dispatcher: Returning event to freenode source
DEBUG core.dispatcher: Received event from freenode source
DEBUG core.dispatcher: {'account': None, 'responses': [{'reply': u'Excuse me?', 'target': u'', 'source': u'freenode'}], 'source': u'freenode', 'addressed': True, 'processed': True, 'time': 1246887557.587127, 'identity': 2, 'message': {'raw': u'*** Your host is holmes.freenode.net[shakermaker.preshweb.co.uk/6667], running version hyperion-1.0.2b', 'deaddressed': u'*** Your host is holmes.freenode.net[shakermaker.preshweb.co.uk/6667], running version hyperion-1.0.2b', 'clean': u'*** Your host is holmes.freenode.net[shakermaker.preshweb.co.uk/6667], running version hyperion-1.0.2b', 'stripped': u'*** Your host is holmes.freenode.net[shakermaker.preshweb.co.uk/6667], running version hyperion-1.0.2b'}, 'type': u'notice', 'public': False, 'channel': u'', 'sender': {'nick': u'', 'connection': u'', 'id': u''}}
DEBUG core.dispatcher: Returning event to freenode source