Make server work with IPv6

bin/instance

@@ -56,7 +56,7 @@ db.connect(dbString, function() {
     }); 
   }
 
-  var server = app.listen(app.get('port'), function() {
+  var server = app.listen(app.get('port'), '::', function() {
     debug('Express server listening on port ' + server.address().port);
   });
 });