Fixed It is possible to set non-selectable styles as default

[Jeremy]

Reproduction Steps:

1. Have a site with 2 styles
2. Disable one of the two styles (the non-default style)
3. Reload page
4. Click the radio button on the non-selectable, non-default style to set it as default
5. Reload forum

Expected behavior:
Receive error message at step 4 - "You cannot prevent users from selecting the default style."

Actual behavior:
Default style is changed and shown to user, regardless of if it is selectable or not.

 

[Mike]

Technically, preventing people from disabling the default style isn't 100% necessary - it will be still be used. That said, we enforce it in some places, so we should enforce it everywhere.