diagnostics: Use app.html instead of simple_app.html

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

plinth/modules/diagnostics/diagnostics.py

@@ -45,6 +45,7 @@ def index(request):
     return TemplateResponse(
         request, 'diagnostics.html', {
             'title': diagnostics.name,
+            'name': diagnostics.name,
             'description': diagnostics.description,
             'is_running': _running_task is not None,
             'manual_page': diagnostics.manual_page,

plinth/modules/diagnostics/templates/diagnostics.html

@@ -1,4 +1,4 @@
-{% extends 'simple_app.html' %}
+{% extends 'app.html' %}
 {% comment %}
 #
 # This file is part of FreedomBox.