fix carousel slugs

apps/main/models.py

@@ -279,6 +279,11 @@ class Carousel(models.Model):
 
     @property
     def slug(self):
+        if hasattr(self.content_object, 'slugs'):
+            try:
+                return next(iter(self.content_object.slugs.values()))
+            except StopIteration:
+                return None
         if hasattr(self.content_object, 'slug'):
             return self.content_object.slug