manager: fix HTTP status code of reorder call (#17261)

combo/manager/views.py

@@ -359,7 +359,7 @@ def cell_order(request, page_pk):
             cell.order = new_order
             cell.placeholder = new_placeholder
             cell.save()
-    return HttpResponse(status=206)
+    return HttpResponse(status=204)
 
 
 def page_order(request):

tests/test_manager.py

@@ -442,7 +442,7 @@ def test_edit_cell_order(app, admin_user):
 
     app = login(app)
     resp = app.get('/manage/pages/%s/order?%s' % (page.id, urllib.urlencode(params)))
-    assert resp.status_code == 206
+    assert resp.status_code == 204
     for i, cell in enumerate(cells):
         assert TextCell.objects.get(id=cell.id).order == new_order[i]