Web: prevent error when notification popover is empty

web/app/src/components/FooterPopup.vue

@@ -46,6 +46,7 @@ onMounted(() => {
 });
 
 function _scrollToBottom() {
+  if (notifs.empty) return;
   tabulator.scrollToRow(notifs.lastID, "bottom", false);
 }
 function _subscribeToPinia() {

web/app/src/stores/notifications.js

@@ -22,6 +22,9 @@ export const useNotifs = defineStore('notifications', {
     hideTimerID: 0,
     lastID: 0,
   }),
+  getters: {
+    empty: (state) => state.history.length == 0,
+  },
   actions: {
     /**
      * Add a simple notification.