PsPad 5.0.0 from rapps, local help has two vertical scrollbars

0.4.11-RC-34-g5e059e7 gcc dbg linux is affected
PsPad 5.0.0 from rapps
I did notice that today for the first time.

(eventually it is needed to have Gecko installed to view the affected dlg)

Reproduction steps
In the main app select help/help local from menubar

Observed result
Two vertical scrollbars are shown erroneously
0.4.11-RC-34-g5e059e7_pspad5_0_0_2verticalScrollbars.webm
0.4.11-RC-34-g5e059e7_pspad5_0_0_2verticalScrollbars.log

Expected result
Only one vertical scrollbar
xpsp3.webm