Fixed user registration bug when no import sources are selected

What does this MR do and why?

Resolves #423722 (closed).

Fixed user registration bug when no import sources are selected

Screenshots or screen recordings

Before	After

How to set up and validate locally

More details in #423722 (closed)

1. Simulate SAAS locally with GDK
2. Login as root
3. Navigate to /admin/application_settings/general
4. Under "Visibility and access controls" tab, Untick all Import Sources
5. Logout and register a new user at http://gdk.test:3000/users/sign_up
6. Select radio options "Just me" and "Create a new project"
7. Confirm redirected to http://gdk.test:3000/users/sign_up/groups/new with a working form

Note if trapped on the broken form page when testing, delete the session cookie to be able to log back in.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #423722 (closed)