builder: Fix ordering of arch-specific build options
builder: Fix ordering of arch-specific build options

The arch-specific options override the generic ones,
not the other way around.

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