Made test_change_list_sorting_model_admin_reverse's assertions more specific.

The test could fail on databases like CockroachDB that use non-serial
primary keys if the numbers (2000, etc.) appeared in the pk values.

tests/admin_views/tests.py

@@ -448,24 +448,26 @@ class AdminViewBasicTest(AdminViewBasicTestCase):
         method in reverse order (i.e. admin_order_field uses the '-' prefix)
         (column 6 is 'model_year_reverse' in ArticleAdmin)
         """
+        td = '<td class="field-model_property_year">%s</td>'
+        td_2000, td_2008, td_2009 = td % 2000, td % 2008, td % 2009
         response = self.client.get(reverse('admin:admin_views_article_changelist'), {'o': '6'})
         self.assertContentBefore(
-            response, '2009', '2008',
+            response, td_2009, td_2008,
             "Results of sorting on ModelAdmin method are out of order."
         )
         self.assertContentBefore(
-            response, '2008', '2000',
+            response, td_2008, td_2000,
             "Results of sorting on ModelAdmin method are out of order."
         )
         # Let's make sure the ordering is right and that we don't get a
         # FieldError when we change to descending order
         response = self.client.get(reverse('admin:admin_views_article_changelist'), {'o': '-6'})
         self.assertContentBefore(
-            response, '2000', '2008',
+            response, td_2000, td_2008,
             "Results of sorting on ModelAdmin method are out of order."
         )
         self.assertContentBefore(
-            response, '2008', '2009',
+            response, td_2008, td_2009,
             "Results of sorting on ModelAdmin method are out of order."
         )