It is possible to set a Email for a Organization. This Email is optional and only used to be displayed on the profile page. However, once you set an EMail, you can no longer remove it. This PR fixes that.
While working on the tests, I found out, that the API returns a 500 when trying to set an invalid EMail. I fixed that too. It returns a 422 now.
Fixes #4567
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/5517
Reviewed-by: Gusted <gusted@noreply.codeberg.org>
Reviewed-by: Otto <otto@codeberg.org>
Co-authored-by: JakobDev <jakobdev@gmx.de>
Co-committed-by: JakobDev <jakobdev@gmx.de>
