remove alert('wat')

I was testing whether the utf8 issue[1] actually prevents compiling.
[1]: http://github.com/jashkenas/coffee-script/issues#issue/421

it doesn't, so all is well.

4chan_x.js

@@ -944,5 +944,4 @@ cursor: pointer; \
     callback();
   }
   document.body.addEventListener('DOMNodeInserted', nodeInserted, true);
-  alert('wat');
 })();