Bug: scroll bars in preference dialog

[lure23]

This is a slight visual annoyance, but I decided to mention it.

It may be correct on Windows (based on some screen shots I've seen) but occurs on OS X (Fusion 360 1.8.604).

- If all material fits in the dialog, vertical scroll bar should not be visible

- Scrolling down on vertical scroll bar should stop once all options are visible (and not proceed beyond)

Currently, this is not the situation as these pictures show.

The horizontal scroll bar seems to be working correctly (if one scales the dialog smaller).

I presume there is an invisible UI element in the pages with "plentiful room for new options" or something. This is not a good idea since it affects the scroll bar as well, making the application think there is more content than is visible for the user.