FIX: display argument in hyperion-qt

[Denrage]

Summary
This fixes the display argument in hyperion-qt, so it actually uses the display given to the program through argument.

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• Bugfix
• Feature
• Code style update
• Refactor
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• No

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[hyperion-project]

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[hyperion-project]

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[Lord-Grey]

@Denrage Thanks for your contribution!

If Display can always be an integer only, then this fix should be applied to other grabbers with "Display" too,
Could you also fix hyperion-osx.cpp?

[hyperion-project]

Here is your new link to your workflow artifacts.

[Denrage]

I fixed it for osx too. Am i able to test it without a mac?

[Lord-Grey]

@tpmodding Could you Test the fix on MacOS?

[tpmodding]

works

[Paulchen-Panther]

I thank you on behalf of everyone for your help.