Bilateral sharpen - reducing multipass disables the dialog

[davidh]

If you switch from 2-pass back to 1-pass sharpening from Pass 2 tab while you are on the pass 2 tab, the dialog stops functioning. With 3 pass sharpening it is similar.

1. open Bilateral sharpen
2. go to settings and and enable 2 pass sharpening
3. optionally make some visibly different settings
4. go to the pass 2 tab and change the settings to 1 pass sharpening ->
- the dialog controls continue to display pass 2 tab sliders
- the button 2 gets grayed out but stays pressed,

What is displayed in the dialog preview depends on butons 1 and 2:
if only button 1, or both buttons were pressed, the preview corresponds to pass 1 tab sliders setting
if only button 2 was pressed, the preview displays the input image

Resetting displays the default sliders (pass 1 tab) but they are not functional. The dialog has to be closed and reopened.

[jsachs]

Fixed for next release