Remove faulty DNS memberOf Task
    
    This task was added with a DN colliding with privilege update memberOf
    task being run later and caused this task to be ineffective and thus
    miss some privilege membership, like "SELinux User Map Administrators"
    
    DNS update plugin do not need to run any task at all as privileges
    will be updated later in scope of 55-pbacmemberof.update
    
    https://fedorahosted.org/freeipa/ticket/3877