rpc: fix a comment typo (#16929)

rpc/server.go

@@ -145,7 +145,7 @@ func (s *Server) serveRequest(ctx context.Context, codec ServerCodec, singleShot
 	defer cancel()
 
 	// if the codec supports notification include a notifier that callbacks can use
-	// to send notification to clients. It is thight to the codec/connection. If the
+	// to send notification to clients. It is tied to the codec/connection. If the
 	// connection is closed the notifier will stop and cancels all active subscriptions.
 	if options&OptionSubscriptions == OptionSubscriptions {
 		ctx = context.WithValue(ctx, notifierKey{}, newNotifier(codec))