direct link to extension does not open if not logged in beforehand

A direct link to an extension is only opened correctly if the user is already logged in into the platform. If this is not the case, one gets redirected to the login page. After log in, the user does not get redirected to the extension specified in the link.

Here a link for testing purposes: https://vispa.physik.rwth-aachen.de/server/?workspace:VISPA%20Cluster/codeeditor:CodeEditor:/home/public/auger/examples/energy\_distribution/auger.py

(from redmine: issue id 2414, created on 2016-07-08 by Christian.Glaser, closed on 2016-07-14)