Fix admin redirect by using the url pattern name and not hardcoded URL

src/inventory_project/urls.py

@@ -10,7 +10,7 @@ admin.autodiscover()
 urlpatterns = [  # Don't use i18n_patterns() here
     path('admin/', admin.site.urls),
 
-    url(r'^$', RedirectView.as_view(url='/admin/')),
+    url(r'^$', RedirectView.as_view(pattern_name='admin:index')),
 
     path('ckeditor/', include('ckeditor_uploader.urls')),  # TODO: check permissions?
     path(settings.MEDIA_URL.lstrip('/'), include('django_tools.serve_media_app.urls')),