FIX: tokens: catch non-existing permissions (fixes #738)

frontend/src/views/netdb/Tokens.vue

@@ -476,6 +476,9 @@ export default {
     },
     role_list_has_permission(role_list, permission_name) {
       return role_list.some(role => {
+        if (!(permission_name in this.permissions)) {
+          return false
+        }
         return this.permissions[permission_name].hierarchy_gfk_list.some(gfk => {
           return role.gpk === gfk
         })