Update app.py

app.py

@@ -253,8 +253,6 @@ def merge_alpha(img, sigma=0.0):
         return np.clip(result, 0, 255).astype(np.uint8)
     else:
         raise ValueError(f"Unexpected number of channels: {C}")
-    else:
-        raise ValueError(f"Unexpected number of channels: {C}")
 
 
 @torch.inference_mode()