[BZ 1070277] - (JON3-39) JON should (be able to) block login to a user without roles - Changing the default of the property to true, i.e. enabling the login for user without roles by default.

(cherry picked from commit 4df0d7f411da1a03604e49c6b9d0117965616ca8)
Signed-off-by: Jirka Kremser <jkremser@redhat.com>