Registration: If you fail CAPTCHA once, you have to refresh the page

[WofWca]

Describe the issue

See title

I already tried

• I've read and searched the documentation.
• I've searched for similar issues in this repository.

Steps to reproduce the behavior

1. Go to https://hosted.weblate.org/accounts/register/
2. Fill the fields normally, except for CAPTCHA - enter a wrong answe
3. Click "Register"
4. It will say that the solution was wrong, but will not offer a new challenge, or even accept the correct answer for the previous challenge. Moreover, if you then refresh the page it will say "CSRF verification failed. Request aborted.", so you have to press "Register" again.

Expected behavior

It rejects the submission, and offers a new CAPTCHA attempt.

Screenshots

Exception traceback

No response

How do you run Weblate?

weblate.org service

Weblate versions

No response

Weblate deploy checks

No response

Additional context

No response

[WofWca]

Also I just found out that the same pain happens if you attempt to register with a username that already exist, then try changing it to something else.

[github-actions]

Thank you for your report; the issue you have reported has just been fixed.

• In case you see a problem with the fix, please comment on this issue.
• In case you see a similar problem, please open a separate issue.
• If you are happy with the outcome, don’t hesitate to support Weblate by making a donation.

[WofWca]

There's still a bit of an issue that if you enter a username that already exists and enter the CAPTCHA correctly and submit the form, the captcha challenge will refresh, but it won't show it, so form submission will fail again.

I think it would be ideal if users had to submit the CAPTCHA only once per successful registration.