message: remove unused variable in Test
  Summary: fixes
diff: @@ -872,13 +872,11 @@ TEST_F(QuicLossFunctionsTest, TestMarkPacketLossNoMerge) {
  auto& packet1 =
  getFirstOutstandingPacket(*conn, PacketNumberSpace::AppData)->packet;
  - auto packetNum = packet1.header.getPacketSequenceNum();
  markPacketLoss(*conn, packet1, false);
  EXPECT_EQ(stream1->retransmissionBuffer.size(), 2);
  EXPECT_EQ(stream1->lossBuffer.size(), 1);
  auto& packet3 =
  getLastOutstandingPacket(*conn, PacketNumberSpace::AppData)->packet;
  - packetNum = packet3.header.getPacketSequenceNum();
  markPacketLoss(*conn, packet3, false);
  EXPECT_EQ(stream1->retransmissionBuffer.size(), 1);
  EXPECT_EQ(stream1->lossBuffer.size(), 2);
  