update the listen command to not specify the ip address

bin/www

@@ -36,7 +36,7 @@ var server = http.createServer(app);
  * Listen on provided port, on all network interfaces.
  */
 
-server.listen(port, '0.0.0.0');
+server.listen(port);
 server.on('error', onError);
 server.on('listening', onListening);