Allow quic_toy_server to only use IETF QUIC

gfe-relnote: n/a, test-only
PiperOrigin-RevId: 268771484
Change-Id: I0546c2758165c4f16e7b2a3cda008e34643fdb04
diff --git a/quic/core/quic_dispatcher.cc b/quic/core/quic_dispatcher.cc
index 6a4ce01..b8e7f0c 100644
--- a/quic/core/quic_dispatcher.cc
+++ b/quic/core/quic_dispatcher.cc
@@ -204,7 +204,10 @@
       allow_short_initial_server_connection_ids_(false),
       expected_server_connection_id_length_(
           expected_server_connection_id_length),
-      should_update_expected_server_connection_id_length_(false) {}
+      should_update_expected_server_connection_id_length_(false) {
+  QUIC_DLOG(INFO) << "Created QuicDispatcher with versions: "
+                  << ParsedQuicVersionVectorToString(GetSupportedVersions());
+}
 
 QuicDispatcher::~QuicDispatcher() {
   session_map_.clear();