Fix ‘this is undefined’ error

lib/www/client/source/src/views/Log.vue

@@ -532,7 +532,7 @@ export default {
     },
 
     async saveEvent (event) {
-      function callback (err, res) {
+      const callback = (err, res) => {
         if (!err && res.ok) {
           this.showSnack(["New event saved", "success"]);
           this.queuedReload = true;