Ignoring loss of undecryptable packets

[WesleyRosenblum]

https://tools.ietf.org/id/draft-ietf-quic-recovery-31.html#section-7.4

During the handshake, some packet protection keys might not be available when a packet arrives and the receiver can choose to drop the packet. In particular, Handshake and 0-RTT packets cannot be processed until the Initial packets arrive and 1-RTT packets cannot be processed until the handshake completes. Endpoints MAY ignore the loss of Handshake, 0-RTT, and 1-RTT packets that might have arrived before the peer had packet protection keys to process those packets. Endpoints MUST NOT ignore the loss of packets that were sent after the earliest acknowledged packet in a given packet number space.