remove tabs from html

backend/app/templates/500.html

@@ -2,8 +2,8 @@
 
 {% block content %}
 
-	<h2>An unexpected error has occurred.</h1>
-	<p>Administrator has been notified.</p>
-	<p><a href="{{ url_for('index') }}">Back</a></p>
+  <h2>An unexpected error has occurred.</h1>
+  <p>Administrator has been notified.</p>
+  <p><a href="{{ url_for('index') }}">Back</a></p>
 
 {% endblock %}