Backport Bottles thumbnail fix

src/importer/sources/bottles_source.py

@@ -69,6 +69,9 @@ class BottlesSourceIterator(SourceIterator):
                 bottles_location = self.source.data_location.root / "bottles"
 
             bottle_path = entry["bottle"]["path"]
+
+            additional_data = {}
+            if entry["thumbnail"]:
                 image_name = entry["thumbnail"].split(":")[1]
                 image_path = bottles_location / bottle_path / "grids" / image_name
                 additional_data = {"local_image_path": image_path}