The width of list view header of Cppcheck analysis results window automatic adjustment

[louislau86]

We must adjust the width of list view header by manual when a new checking finished and showing the results. I think it would be automatic adjust by setting header width attribute as auto, and i tried that it took effect.

[VioletGiraffe]

The width is already set to "Auto" so I'm not sure what else can be done. If you know and tested a solution, please submit a pull request.