The same code change should still work. The link you need to change is now here:
https://github.com/moodle/moodle/blob/v2.9.1/mod/quiz/renderer.php#L699
The same code change should still work. The link you need to change is now here:
https://github.com/moodle/moodle/blob/v2.9.1/mod/quiz/renderer.php#L699