Resolve "Check if user has person when displaying seating plan menu item"

Closes #14 (closed)

aleksis/apps/stoelindeling/frontend/index.js

+import { hasPersonValidator } from "aleksis.core/routeValidators";
+
 export default
   {
     meta: {
       inMenu: true,
       titleKey: "stoelindeling.menu_title",
       icon: "mdi-view-list-outline",
+      validators: [
+        hasPersonValidator
+      ],
     },
     props: {
       byTheGreatnessOfTheAlmightyAleksolotlISwearIAmWorthyOfUsingTheLegacyBaseTemplate: true,