tests: don't distinguish unicode data sources in py3 (#36515)

tests/test_admin_pages.py

@@ -21,6 +21,7 @@ import pytest
 from webtest import Upload
 import mock
 
+from django.utils import six
 from django.utils.six import StringIO, BytesIO
 from django.utils.six.moves.urllib import parse as urlparse
 
@@ -4812,7 +4813,10 @@ def test_data_sources_view(pub):
     data_source.store()
     resp = app.get('/backoffice/settings/data-sources/%s/' % data_source.id)
     assert 'Preview' in resp.text
-    assert 'error: not a string' in resp.text
+    if six.PY2:
+        assert 'error: not a string' in resp.text
+    else:
+        assert 'Domicilié' in resp.text
 
     # check json
     json_file_path = os.path.join(pub.app_dir, 'test.json')