Publish the followed events once the controller's consumer exists

Made from now since issue 248, the consumer does not replay what was
published before it; the test raced the controller's start and published
first.

internal/link/receive_nats_test.go

@@ -315,6 +315,12 @@ func TestNatsTheEventsTheControllerFollowsArriveAndAreAcknowledged(t *testing.T)
 	ctx, stop := context.WithCancel(context.Background())
 	defer stop()
 	go func() { _ = s.Serve(ctx) }()
+	// The controller's event consumer is made from now (novox/hq issue 248): what was published before
+	// it existed is history it never replays. So the announcements are made once it is there.
+	eventually(t, "the controller's event consumer being made", func() bool {
+		_, err := js.Context().ConsumerInfo("EVENTS", broker.ControllerName)
+		return err == nil
+	})
 
 	moved, _ := json.Marshal(Upgraded{Module: "gitea", Commit: "abcdef0123"})
 	if _, err := js.Context().Publish(broker.ControllerFollows[0], moved); err != nil {