Fixed login message visible

/label bug

Closes #968 (closed)

Previous behaviour

Steps to reproduce:

1. Do not log in.
2. Go to an event for which no registration is required.
3. A login button appears.

New behaviour

Steps to validate that it works:

1. Do not log in.
2. Go to an event for which no registration is required.
3. No login button appears, a message "no registration required" is displayed.