The script points to a repo that doesn't exists anymore

[tuconeves]

KDE repo was moved to

https://cdn.kde.org/flatpak/

and xwaylandvideobridge is now at
https://cdn.kde.org/flatpak/xwaylandvideobridge-nightly/

[JerrySM64]

Thank you for the heads up! I created the PR, but have to delay the merge until I have access to a Linux machine to test it on.