Changing the token owner changes also the manager
    
    This works if the change is made to a token which is owned and managed by the
    same person. The new owner then automatically becomes token's manager unless
    the attribute 'managedBy' is explicitly set otherwise.
    
    https://fedorahosted.org/freeipa/ticket/4681
    
    Reviewed-By: Nathaniel McCallum <npmccallum@redhat.com>