Signing up for an account that is restricted to a certain email address domain fails to display error message

Scenario

• Users tries to sign up for an existing Confluence-only OnDemand instance, through the 'Sign up here' link provided in the login page (only available on instances that allow people to sign up to create their account).
• The ability to sign up is restricted to a certain email address domain, so users that have a different email address don't see any message about the sign up failure, any message stating that they can't sign up with another email address domain, the page only refreshes and they are not able to sign up.

Steps to reproduce

1. Inside your Confluence-only OnDemand instance go to the 'Users' page (within administrative area)
2. Go to the 'User Signup Options'
3. Select the option 'Allow people to sign up to create their account'
4. Mark the option 'Restricted by Domain(s)' and place any domain of your choice (e.g. gmail.com)
5. Save the configuration
6. Log out of the instance
7. Click on the 'Sign up here' link on the login page
8. Fill in the form and use an email address that is not from the domain you chose
9. Click on the 'Sing 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.