Log error code when unknown

quic/core/quic_connection.cc

diff --git a/quic/core/quic_connection.cc b/quic/core/quic_connection.cc
index aa7b55a..e2b295b 100644
--- a/quic/core/quic_connection.cc
+++ b/quic/core/quic_connection.cc
@@ -1308,6 +1308,7 @@
   }
   QUIC_DLOG(INFO) << ENDPOINT << "Received ConnectionClose for connection: "
                   << connection_id() << ", with error: "
+                  << static_cast<uint64_t>(frame.quic_error_code) << " "
                   << QuicErrorCodeToString(frame.quic_error_code) << " ("
                   << frame.error_details << ")";
   if (frame.close_type == GOOGLE_QUIC_CONNECTION_CLOSE &&