Corrected another error in README example code

README.md

@@ -130,7 +130,7 @@ Basic usage
                 print 'Received message "%s"' % message.payload
                 client.send(wspy.TextMessage(message.payload))
 
-            def onclose(self, client):
+            def onclose(self, client, code, reason):
                 print 'Client %s disconnected' % client
 
         EchoServer(('', 8000)).run()