We instead juts SKIP updating the policy, so
1. the MDM ticker will kick in 1 minute time,
2. find the policy misaligned,
3. enter the onMDMPolicyChange,
4. find the s.clientRunning == true
(because it is set to false only in server cleanupConnection,
and not by s.actCancel())
5. call s.actCancel() again if not nil
6. immediately return from <-s.clientGiveUpChan
7. finally call s.restartEngineForMDMLocked()