Merge pull request #2527 from lucas-clemente/reset-pto-when-dropping-packet-number-space

reset the PTO when dropping a packet number space

internal/ackhandler/sent_packet_handler.go

@@ -164,6 +164,7 @@ func (h *sentPacketHandler) dropPackets(encLevel protocol.EncryptionLevel) {
 		h.qlogger.UpdatedPTOCount(0)
 	}
 	h.ptoCount = 0
+	h.numProbesToSend = 0
 	h.ptoMode = SendNone
 }