Log URL when calling Wikia::logBacktrace

GET request parameters will be logged when used in wikia.php request

Example:

```
WikiaException::__construct: Wikia.php line 406 calls wfBacktrace()/WikiaException.php line 58 calls Wikia::logBacktrace()/WikiaDispatcher.class.php line 108 calls WikiaException->__construct()/WikiaApp.class.php line 590 calls WikiaDispatcher->dispatch()/wikia.php line 36 calls WikiaApp->sendRequest() URL: /wikia.php?controller=LyricFind&method=track&pageid=1964
```