Edit header toolSettings levels

Hello,

Is it possible to edit the header tool levels ?
I want to disable H1 and I tried this but it's stil allowing H1 when editing :

```
'toolSettings' => [
        'header' => [
            'activated' => true,
            'placeholder' => 'Header',
	    'defaultLevel'=> 3,
	    'levels'=> [2, 3, 4, 5],
            'shortcut' => 'CMD+SHIFT+H'
        ],
        ...
```