example update: remove unused group csc from fgci admin users
example update: remove unused group csc from fgci admin users

 - the unix group csc was never used, and it caused the users
   to both have admin group as their primary group and be members
   of the group too (they were in it in /etc/groups)
 - if the group is kept user role will fail if it's updated to a version
   after 1.5.1
 - #159

mantti/fgci-tut,CSC-IT-Center-for-Science/fgci-ansible,mantti/fgci-tut,mantti/fgci-tut