Fix for Wii U browser

Apparently it doesn't send the login cookie if you explicitly set the
socket.io transports to prefer websockets.  Magic.

www/js/callbacks.js

@@ -1138,7 +1138,6 @@ setupCallbacks = function() {
             }
 
             var opts = {
-                transports: ["websocket", "polling"],
                 secure: chosenServer.secure
             };