Fix warning message when updating

Since stable cascade came out, I've updated more than once in a day.

And I've got this message, the last 2 times, witch I never had before.


But there is no error in the cmd line.

```
To see the GUI go to: http://127.0.0.1:8188
FETCH DATA from: C:\Cui\cu_121_2\ComfyUI_windows_portable\ComfyUI\custom_nodes\ComfyUI-Manager\extension-node-map.json
Update ComfyUI
CUSTOM NODE PULL: Success
Install: pip packages
FETCH DATA from: https://raw.githubusercontent.com/ltdrdata/ComfyUI-Manager/main/custom-node-list.json
All extensions are already up-to-date.
```

And Comfy UI updated successfully, because I have noticed the latest cascade commits.

I think this happened, because there were no extensions to update ( ? )

The first time it happened, I think the Manager was updated, according to the cmd line ( but I'm not sure ).