Added comment for clarity

Co-authored-by: Alex Garel <[email protected]>

openfoodfacts/images.py

@@ -192,6 +192,7 @@ def extract_source_from_url(url: str) -> str:
     if url_path.endswith(".json"):
         url_path = str(Path(url_path).with_suffix(".jpg"))
 
+    # normalize windows path to unix path
     return url_path.replace("\\", "/")