not error message when user with restricted doamin sign up for an account

Description

The user tried to sign up via User Signup Option with a not allowed domain. However, when the user submits the information, Confluence does not show the error that the user is not able to signup and only refreshed the page.

Steps to reproduce
1. Administration > User Management > User Signup Options
2. Select the option 'Allow people to sign up to create their account'
3. Mark the option 'Restricted by Domain(s)' and add domains of your choice
4. Save the configuration
5. Log out of the instance
6. Click on the 'Sign up here' link on the login page
7. Fill in the form and use an email address that is not from the domains you chose
8. Click on the 'Sign up' button

Expectation
Display a message stating that the user cannot sign up with the email address desired and the sign up has failed.

Actual Behavior
Nothing happens, the page just refreshes.

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available