Update app.py

app.py

@@ -37,7 +37,7 @@ moondream.eval()
 @spaces.GPU(duration=10)
 def answer_question(img, prompt):
     if img is None:
-        return
+        yield ""
 
     image_embeds = moondream.encode_image(img)
     streamer = TextIteratorStreamer(tokenizer, skip_special_tokens=True)
@@ -61,7 +61,7 @@ def answer_question(img, prompt):
 @spaces.GPU(duration=10)
 def caption(img, mode):
     if img is None:
-        return
+        yield ""
 
     streamer = TextIteratorStreamer(tokenizer, skip_special_tokens=True)
     thread = Thread(