core: Fix admin@internal permissions

Fix permissions for admin@internal user by setting
last_admin_check_status to true. The same is done in
AddPermissionCommand if admin role is assigned to user.

Change-Id: Iacc197cbff33d74cf8f2d7bd1b18c31092fdea43
Bug-Url: https://bugzilla.redhat.com/1057087
Signed-off-by: Martin Perina <mperina@redhat.com>