Use QuicSession::transport_version() instead of QuicConnection::transport_version() to make code cleaner.

gfe-relnote: code cleanup, not protected.
PiperOrigin-RevId: 267628510
Change-Id: I2b28c42ec2345870905e7e5d7e88721be86ad6e4
diff --git a/quic/core/quic_crypto_server_handshaker.cc b/quic/core/quic_crypto_server_handshaker.cc
index ab381d7..49e7209 100644
--- a/quic/core/quic_crypto_server_handshaker.cc
+++ b/quic/core/quic_crypto_server_handshaker.cc
@@ -258,7 +258,7 @@
   send_server_config_update_cb_ = cb.get();
 
   crypto_config_->BuildServerConfigUpdateMessage(
-      session()->connection()->transport_version(), chlo_hash_,
+      session()->transport_version(), chlo_hash_,
       previous_source_address_tokens_, session()->connection()->self_address(),
       GetClientAddress().host(), session()->connection()->clock(),
       session()->connection()->random_generator(), compressed_certs_cache_,