Disabled combobox in drift_correct is re-enabled after switching items

[JdenHartog]

In the pygaze_drift_correct plug-in in OpenSesame 2.9.6 on Windows 7 x64: The Target color and Target style both get disabled (grayed out) after unchecking Show display with drift-correction target as they should. But after switching to another item in the Overview and switching back to the pygaze_drift_correct item; the Target color (type line_edit) is still disabled but the Target style (type combobox) is re-enabled!

I also reported this as an OpenSesame issue https://github.com/smathot/OpenSesame/issues/347 but it appears to be a plug-in issue. Overriding edit_widget in the plug-in seems to work.