use homepage link to redirect from error page (#1260)

templates/error.html.twig

@@ -42,7 +42,7 @@
             {{ errorMessageTrans }}
         </p>
         <p>
-            <a class="btn btn-primary" href="{{ path('dashboard') }}">{{ 'dashboard.title'|trans }}</a>
+            <a class="btn btn-primary" href="{{ path('homepage') }}">{{ 'dashboard.title'|trans }}</a>
         </p>
     {% endblock %}
 {% endblock %}