set transition time if health status is unknown

Signed-off-by: Manuel Kieweg <mail@manuelkieweg.de>

controller/appcontroller.go

@@ -1543,6 +1543,7 @@ func (ctrl *ApplicationController) processAppRefreshQueueItem() (processNext boo
 	if hasErrors {
 		app.Status.Sync.Status = appv1.SyncStatusCodeUnknown
 		app.Status.Health.Status = health.HealthStatusUnknown
+		app.Status.Health.LastTransitionTime = metav1.Now()
 		patchMs = ctrl.persistAppStatus(origApp, &app.Status)
 
 		if err := ctrl.cache.SetAppResourcesTree(app.InstanceName(ctrl.namespace), &appv1.ApplicationTree{}); err != nil {