Should closeTab icon be hidden when highlightModifiedTabs is true?

Using this config:
```json
"workbench.editor.tabCloseButton": "off",
"workbench.editor.highlightModifiedTabs": true,
```
\- dirty files still take space for closing button (and shifting all tabs). 

It makes sense that it worked that way when the only option to show `modified` state of files was the icon. 

Should it take into account highlighting option and not change tab width now?