tests: Fix missing end quote of regex pattern
tests: Fix missing end quote of regex pattern

Not sure how this didn't cause a unit test failure

Closes: #2803
Approved by: matthiasclasen

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