Temporary fix for the styles of the error 500 page

Author: javiereguiluz

templates/bundles/TwigBundle/Exception/error500.html.twig

@@ -10,6 +10,11 @@
 
 {% extends 'base.html.twig' %}
 
+{% block stylesheets %}
+    {{ parent() }}
+    <link rel="stylesheet" href="/build/css/app.4aa95248.css">
+{% endblock %}
+
 {% block body_id 'error' %}
 
 {% block main %}