testlibrary: Fix a typo in a URL
testlibrary: Fix a typo in a URL

Closes: #3066
Approved by: alexlarsson

matthiasclasen/flatpak,flatpak/flatpak,flatpak/flatpak,matthiasclasen/flatpak,flatpak/flatpak,flatpak/flatpak,matthiasclasen/flatpak,matthiasclasen/flatpak,matthiasclasen/flatpak,flatpak/flatpak