Foreman settings should not be viewed/edited by non admin users
fixes #1050 - Foreman settings should not be viewed/edited by non admin user
refs #1050 removing model level authorization from settings table
this seems more trouble than its worth, as settings needs to be
checked/updated every time foreman is starting.
this leads to potenitail issue when login is enabled, or the admin user is missing etc
which can simply break foreman with very little benefit to security.