Skip queries until group is loaded fully

aleksis/apps/lesrooster/frontend/components/timetable_management/TimetableManagement.vue

@@ -234,7 +234,8 @@ export default defineComponent({
   },
   computed: {
     readyForQueries() {
-      return this.internalTimeGrid !== null && this.selectedGroup !== null;
+      // Non-typesafe check to also handle undefined
+      return this.internalTimeGrid != null && this.selectedGroup != null && this.selectedGroup.id != null;
     },
     lessons() {
       return this.lessonObjects