ship with base mellon template, required for error handling (#27132)

src/authentic2_auth_fedict/templates/mellon/base.html

@@ -0,0 +1,11 @@
+{% extends "authentic2/base.html" %}
+
+{% block extra_scripts %}
+   {% block mellon_extra_scripts %}
+   {% endblock %}
+{% endblock %}
+
+{% block content %}
+   {% block mellon_content %}
+   {% endblock %}
+{% endblock %}