Don't warn about non-existant warning on older GCC
Don't warn about non-existant warning on older GCC

dominicgs/GreatFET-experimental,greatscottgadgets/greatfet,dominicgs/GreatFET-experimental,greatscottgadgets/greatfet,greatscottgadgets/greatfet,dominicgs/GreatFET-experimental,greatscottgadgets/greatfet