White line when changing language

[CennoxX]

When changing the language of 7-Zip a white line between the menu and the toolbar appears.

Steps to Reproduce the Issue

1. Open 7-Zip File Manager
2. Tools > Options… > Language (> Change Language) > press OK

[ozone10]

@CennoxX
thank you for creating issue. I already know about it. Also when changing toolbar appearance that white line will appear.
These settings are "set and forget" types, which means that users don't usually change them often.
Restarting app will usually fix it. And since it's small issue and my reluctance to do more changes in upstream code, fix for this will have low priority.

Another known issues include second panel not in dark mode if 7zip started with single panel and second is then enabled.
In window mode changing between mode will not redraw icon in comboboxex, clicking on comboboxex will fix it.
In window mode changing between mode will make disabled static text look strange.

For now these issues won't be fixed as I will be doing something else.

btw
My main focus for now will be gridlines and some PRs for n++.