fix animation duration broken

app.py

@@ -115,7 +115,8 @@ def convert_webp_to_images(webp_path):
         image.seek(i)
         frame = image.copy()
         frames.append(frame)
-        duration = getattr(frame.info,"duration",100)
+        # frame.info must be dictionary
+        duration = frame.info.get("duration",100)
         durations.append(duration)
   else:# webp never happen?
       frames.append(image)