QGroupBox's indicator displayed incorrectly when UNfocused

[tsilia]

Another issue with the QGroupBox's checkbox (indicator sub-element).

• QDarkStyle: latest master
• OS: Windows 10
• Qt v5.12.2
  Language: C++

When focused, QGroupBox's checkbox (indicator sub-element) is displayed in smaller size than any normal checkbox:

Looks like the style hasn't been applied to the sub-element.

Expected Result:
The icon of the indicator sub-element of a QGroupBox should look the same way any normal checkbox does.

[goanpeca]

Thanks for reporting @tsilia !

[dpizetta]

Close in release v2.8.1 :) Tks for contributing!