Made a test less Django version dependent.

Author: jezdez

tests/panels/test_staticfiles.py

@@ -19,7 +19,7 @@ def test_default_case(self):
         self.panel.process_request(self.request)
         self.panel.process_response(self.request, self.response)
         self.assertIn('django.contrib.staticfiles.finders.'
-                      'AppDirectoriesFinder (87 files)', self.panel.content)
+                      'AppDirectoriesFinder', self.panel.content)
         self.assertIn('django.contrib.staticfiles.finders.'
                       'FileSystemFinder (1 file)', self.panel.content)
         self.assertEqual(self.panel.num_used, 0)