[test] silence lgdb warning about passing str instead of unicode

test/unittest_notifications.py

@@ -21,7 +21,7 @@ class ForgotTC(CubicWebTC):
         MAILBOX[:] = []
         self.assertEqual(len(MAILBOX), 0)
         with self.repo.internal_cnx() as cnx:
-            cnx.call_service('forgotpwd_send_email', use_email='test_user1@logilab.fr')
+            cnx.call_service('forgotpwd_send_email', use_email=u'test_user1@logilab.fr')
             cnx.commit()
         self.assertEqual(len(MAILBOX), 1)
         self.assertNotIn('None', MAILBOX[0].content)
@@ -30,13 +30,13 @@ class ForgotTC(CubicWebTC):
         MAILBOX[:] = []
         self.config.global_set_option('base-url', 'http://babar.com/')
         with self.repo.internal_cnx() as cnx:
-            cnx.call_service('forgotpwd_send_email', use_email='test_user2@logilab.fr')
+            cnx.call_service('forgotpwd_send_email', use_email=u'test_user2@logilab.fr')
             cnx.commit()
         self.assertIn('http://babar.com/', MAILBOX[0].content)
 
         self.config.global_set_option('https-url', 'https://babar.com/')
         with self.repo.internal_cnx() as cnx:
-            cnx.call_service('forgotpwd_send_email', use_email='test_user3@logilab.fr')
+            cnx.call_service('forgotpwd_send_email', use_email=u'test_user3@logilab.fr')
             cnx.commit()
         self.assertIn('https://babar.com/', MAILBOX[1].content)