message: Fix Check for inactive courses and units
diff: @@ -92,7 +92,10 @@ export class NotificationController {
  }
  async createNotification(user: IUser, text: string, changedCourse?: ICourse, changedLecture?: ILecture, changedUnit?: IUnit) {
  - if (!changedCourse.active || !changedUnit.visible) {
  + if (changedCourse && !changedCourse.active) {
  + return;
  + }
  + if (changedUnit && !changedUnit.visible && changedCourse.active) {
  return;
  }
  const notification = new Notification();
  