Added auth.currentUser check

[cph-kiwi]

Description

The Next button was not working for unauthenticated users of the quiz page after they had selected an answer. The problem should be fixed now.

Fixes # https://github.com/HackYourFuture-CPH/Guide-IT/issues/219

How to test?

Open the branch, run "npm run dev", then follow the quiz through as an unauthenticated user.

Checklist

• [x] I have performed a self-review of my own code
• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [x] This PR is ready to be merged and not breaking any other functionality

[ghost]

This does not work for me. If im logged in i can go through the test, but if im not logged ind, nothing happens when i press next. I get the following response from the API error 403 'error "Forbidden"'

[cph-kiwi]

Ok @ditlevHYF . I'll check it out.

[Enqira]

Tested it, works as it should for me.