Avoid retransmitting of packets with discarded keys. Sections 4.10.1 and 4.10.2 of quic transport describe discarding of initial and handshake keys. Since the keys are discarded, we no longer need to retransmit packets and corresponding queues should be emptied. This patch removes previously added workaround that did not require acknowledgement for initial packets, resulting in avoiding retransmission, which is wrong because a packet could be lost and we have to retransmit it.