[5.x] Fix error toast when logging in.

[jelleroorda]

Fixes #9132.

Thanks @rrelmy for debugging it!

[duncanmcclean]

Thanks for this pull request! This toast has been driving me mad for months 😅

Go to login page
Click «Forgot password»
Click «I remember my password» to go back to login
Enter correct credentials

While this PR does fix the first variant identified in the comment on the related issue, it doesn't fix this second variant, where you login after visiting the password reset page. 🤔

[jelleroorda]

Hmm yea right. I guess we’ll have to single out all “authentication routes?” Or do you have a better suggestion?

[jasonvarga]

Sorry for the delay. Thanks everyone involved in figuring this out!