run: Fix e.g. --filesystem=xdg-config/foo without :create
run: Fix e.g. --filesystem=xdg-config/foo without :create

Fixes https://github.com/flatpak/flatpak/issues/463

matthiasclasen/flatpak,GeorgesStavracas/flatpak,matthiasclasen/flatpak,flatpak/flatpak,handsome-feng/flatpak,handsome-feng/flatpak,matthiasclasen/flatpak,handsome-feng/flatpak,matthiasclasen/flatpak,GeorgesStavracas/flatpak,flatpak/flatpak,flatpak/flatpak,flatpak/flatpak,matthiasclasen/flatpak,GeorgesStavracas/flatpak,handsome-feng/flatpak,GeorgesStavracas/flatpak,flatpak/flatpak,handsome-feng/flatpak,GeorgesStavracas/flatpak