misc: remove include warning (#36608)

RemovedInDjango20Warning: Passing a 3-tuple to django.conf.urls.include() is deprecated.
Pass a 2-tuple containing the list of patterns and app_name, and provide the namespace argument to include() instead.

passerelle/urls.py

@@ -30,7 +30,7 @@ urlpatterns = [
     url(r'^media/(?P<path>.*)$', login_required(static_serve), {
         'document_root': settings.MEDIA_ROOT,
     }),
-    url(r'^admin/', include(admin.site.urls)),
+    url(r'^admin/', admin.site.urls),
 
     url(r'^manage/access/',
         decorated_includes(manager_required, include(access_urlpatterns))),