fix city model

apps/location/models.py

@@ -178,12 +178,12 @@ class City(models.Model, TranslatedFieldsMixin):
         verbose_name = _('city')
 
     def __str__(self):
-        return self.name_dumped
+        return f'{self.id}: {self.code}'
 
     @property
     def name_dumped(self):
         """Used for indexing as string"""
-        return f'{self.id}: {dumps(self.name)}'
+        return dumps(self.name)
 
     @property
     def image_object(self):