message: Remove unecessary conn_ member from ClientHandshakeCallbackTest
  Summary:
  As per title.
  Pull Request resolved:
diff: @@ -360,7 +360,6 @@ class ClientHandshakeCallbackTest : public ClientHandshakeTest {
  serverCtx->setSupportedVersions({fizz::ProtocolVersion::tls_1_3});
  clientCtx->setClock(std::make_shared<fizz::test::MockClock>());
  setupZeroRttOnServerCtx(*serverCtx, psk_);
  - conn_.version = getVersion();
  }
  void connect() override {
  @@ -383,7 +382,6 @@ class ClientHandshakeCallbackTest : public ClientHandshakeTest {
  protected:
  QuicCachedPsk psk_;
  - QuicConnectionStateBase conn_{QuicNodeType::Client};
  MockClientHandshakeCallback mockClientHandshakeCallback_;
  };
  