Update advanced app tests

Fixed broken tests.

There is still a problem with this assertion which does not pass: https://github.com/Theill11/yii2/blob/95e01899c7aa50fea0e3a38afff293b762dff32f/apps/advanced/frontend/tests/functional/SignupCest.php#L88

This test does pass which seems to be the same:
https://github.com/Theill11/yii2/blob/95e01899c7aa50fea0e3a38afff293b762dff32f/apps/advanced/frontend/tests/functional/LoginCept.php#L25

Related #2606