MINOR: quic_sock: Finalize the QUIC connections.

Add a call to conn_connection_complete() so that to install the mux any
QUIC connection.
diff --git a/src/quic_sock.c b/src/quic_sock.c
index f349932..1a5cf69 100644
--- a/src/quic_sock.c
+++ b/src/quic_sock.c
@@ -66,7 +66,10 @@
 
 	conn_set_owner(cli_conn, sess, NULL);
 
-	return 1;
+	if (conn_complete_session(cli_conn) >= 0)
+		return 1;
+
+	return 0;
 
  out_free_sess:
 	/* prevent call to listener_release during session_free. It will be