message: quic/state/test/AckHandlersTest.cpp: loop variable: do not create a copy, per -Wrange-loop-construct
  Summary:
  This avoids the following errors:
  quic/state/test/AckHandlersTest.cpp:1542:19: error: loop variable 'ackData' creates a copy from type 'const ackPacketData' [-Werror,-Wrange-loop-construct]
diff: @@ -1539,7 +1539,7 @@ TEST_P(AckHandlersTest, TestRTTPacketObserverCallback) {
  // 0 pending callbacks
  EXPECT_EQ(0, size(conn.pendingCallbacks));
  - for (const auto ackData : ackVec) {
  + for (const auto& ackData : ackVec) {
  processAckFrame(
  conn,
  GetParam(),
  