Right top corner does not click "Close" button in hidpi

[rrygl]

It's a standard behavior to do this:

1. Maximize a window
2. Move mouse cursor to the right top most corner
3. Click mouse
4. Expect the "Close" button to be clicked so that windows is closed.

This works as expected with the low dpi version of xfwm4 theme. But with the hidpi xfwm4 theme that top right pixel is not part of the close button but instead part of the window frame. As a result clicking at that location no longer close the windows.

[rrygl]

I was able to work around this issue by changing frame_border_top to 12 and maximized_offset to 0.