Fix user changelist for custom user models

Fixed the user_admin_changelist url for custom user models.

helpdesk/templates/helpdesk/system_settings.html

@@ -1,4 +1,4 @@
-{% extends "helpdesk/base.html" %}{% load i18n %}{% load url from future %}
+{% extends "helpdesk/base.html" %}{% load i18n %}{% load url from future %}{% load user_admin_url %}
 
 {% block helpdesk_title %}{% trans "Change System Settings" %}{% endblock %}
 
@@ -14,6 +14,6 @@
     <li><a href='{% url 'admin:helpdesk_kbcategory_changelist' %}'>{% trans "Maintain Knowledgebase Categories" %}</a></li>
     <li><a href='{% url 'admin:helpdesk_kbitem_changelist' %}'>{% trans "Maintain Knowledgebase Items" %}</a></li>
     <li><a href='{% url 'admin:helpdesk_emailtemplate_changelist' %}'>{% trans "Maintain E-Mail Templates" %}</a></li>
-    <li><a href='{% url 'admin:auth_user_changelist' %}'>{% trans "Maintain Users" %}</a></li>
+    <li><a href='{% url 'changelist'|user_admin_url %}'>{% trans "Maintain Users" %}</a></li>
 </ul>
 {% endblock %}

helpdesk/templatetags/user_admin_url.py

@@ -0,0 +1,22 @@
+"""
+django-helpdesk - A Django powered ticket tracker for small enterprise.
+
+(c) Copyright 2008 Jutda. All Rights Reserved. See LICENSE for details.
+
+templatetags/admin_url.py - Very simple template tag allow linking to the
+                            right auth user model urls.
+
+{% url 'changelist'|user_admin_url %}
+"""
+
+from django import template
+from django.contrib.auth import get_user_model
+
+def user_admin_url(action):
+    user = get_user_model()
+    return 'admin:%s_%s_%s' % (
+        user._meta.app_label, user._meta.model_name,
+        action)
+
+register = template.Library()
+register.filter(user_admin_urlname)