deckard: abort if sendmmsg/recvmmsg are in use
Deckard does not support these and it leads to confusing errors. In long term we need to migrate Deckard to different network backend: https://gitlab.labs.nic.cz/knot/deckard/issues/42
Deckard does not support these and it leads to confusing errors. In long term we need to migrate Deckard to different network backend: https://gitlab.labs.nic.cz/knot/deckard/issues/42