Add managed read permission for the UPG Definition
    
    Since user_add checks the UPG definition to see if UPG is enabled,
    user admins need read access to add users correctly.
    
    All attributes are allowed since UPG Definition is an extensibleObject;
    the needed attributes are not in the schema.
    
    Part of the work for: https://fedorahosted.org/freeipa/ticket/3566
    
    Reviewed-By: Martin Kosek <mkosek@redhat.com>