Updation of undo values after auto save

[swithinasir]

Provide environment information

Hi wkentaro,
This is swithin Asir right now i am exploring your tool which is in github it was nice and i like this tool very much i noticed one bug in this tool that after autosave if i undo the edited markings or annotation the json file is not updating

python --version is 3.7
and labelme version is 5.2.1

What OS are you using?

Unbuntu 18.4

Describe the Bug

After autosave if I undo the edited markings or annotation the json file is not updating

Expected Behavior

After the autosave if i undo the marking or annotation the value should automatically update

To Reproduce

It is solved for saving the value automatically call the save function into the undo function