Fix bad return in Gotify method

src/Alertify/gotify.py

@@ -99,7 +99,7 @@ class Gotify:
             logging.warning(
                 'No client key is configured.  No messages could be retrieved.'
             )
-            return []
+            return dict()
         logging.debug('Fetching existing messages from Gotify')
         return self._call('GET', '/message')['json'].get('messages', [])
 

src/tests/Alertify/test_gotify.py

@@ -62,9 +62,9 @@ class GotifyTest(unittest.TestCase):
 
     def test_messages(self):
         """Test"""
-        self.assertListEqual(
+        self.assertDictEqual(
             self.gotify_client.messages(),
-            [],
+            dict(),
         )
 
     @patch('http.client.HTTPConnection.request')