Fix datasets without downloads

app.py

@@ -41,7 +41,7 @@ def filter_datasets_by_date():
     with open(f"{DATA_PATH}/{date_to}.json") as f:
         ids_to = json.load(f)
     ids = set(ids_to) - set(ids_from)
-    dss = sorted([ds for ds in datasets if ds.id in ids], key=lambda item: item.downloads, reverse=True)
+    dss = sorted([ds for ds in datasets if ds.id in ids], key=lambda item: getattr(item, "downloads", 0), reverse=True)
     return dss