installation: fix for obsolete demosite create

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
access: addition of site specific configuration

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
installation: mrjoe's Flask-Admin

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>