Fix error page
-<!DOCTYPE html>
+<html xmlns:layout="http://www.ultraq.net.nz/thymeleaf/layout"
+ layout:decorate="~{index.html}">
<html lang="en">
<body>
-<div class="container" th:fragment="content">
+<div class="container" layout:fragment="content">
<div class="container-fluid text-sm p-5 bg-light">
<h1 class="display-2">WHOOOOPS</h1>
<p class="lead">Something went wrong!</p>
