Change to the login subsystem for itslearning

After a small change to the login subsystem for itslearning, all users are encouraged to close and re-open their webbrowser before they try to login to itslearning again. 

The first time, users are also encouraged to login to itslearning directly via https://arcada.itslearning.com/

This applies especially if the old browser session has been active for a longer period of time.