Fixed login message visible

Ghost User
2020-02-19T21:47:58+01:00

/label ~bug

Closes #968

#### 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.