Non Ascii characters wrong in Windows installer

[Rumbah2]

Actual behaviour

At least with German language, the windows installer of USDX does not display Umlauts correctly. They are just black boxes with a question mark inside.

Expected behaviour

The Umlauts are displayed correctly, like äöüßÄÖÜ

Steps to reproduce

1. Start the installer of USDX 2024.5.1 for Windows on a German Windows 11
2. You can see the wrong Umlauts

Details

Provide some additional information:

• USDX version: 2024.5.1 Windows installer
• Operating System + version: Windows 11

[barbeque-squared]

These texts are coming from https://github.com/UltraStar-Deluxe/USDX/blob/master/installer/languages/German.nsh#L78 where they do have umlauts.

Iirc I cannot debug/run the installer at all on my Windows PC.

(if it was only one or two I'd probably just 'fix' it by changing the words to not have special characters, but they're all throughout the installer and I have a suspicion this might also affect other languages then)

[DeinAlptraum]

It seems our installer is missing the Unicode true flag, but adding it produces a broken installer (Unable to elevate) ...