[damned-lies] tests.py: use Unicode quotes

[Claude Paroz <claudep src gnome org>]

commit 183740446bb6c92aaeaead21fdb580dae2814ec1
Author: Rafael Fontenelle <rffontenelle gmail com>
Date:   Thu Aug 30 13:09:59 2018 +0000

    tests.py: use Unicode quotes

 stats/tests/tests.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/stats/tests/tests.py b/stats/tests/tests.py
index 03c4ad80..d51aba2b 100644
--- a/stats/tests/tests.py
+++ b/stats/tests/tests.py
@@ -797,7 +797,7 @@ class UtilsTests(TestCase):
         self.assertIn('xmltags: Different XML tags', result)
 
         result = utils.check_po_quality('unexisting/path.po', ['xmltags'])
-        self.assertEqual(result, "The file 'unexisting/path.po' does not exist")
+        self.assertEqual(result, "The file “unexisting/path.po” does not exist")
 
 
 class OtherTests(TestCase):