Set `last_frame` directly
Set `last_frame` directly

Closes https://github.com/PistonDevelopers/piston/issues/534

caldwell/piston,axelmagn/piston,PistonDevelopers/piston,oldmanmike/piston,Potpourri/piston,tempbottle/piston,PistonDevelopers/piston,mitchmindtree/piston,bvssvni/piston,KevinFrans3/piston,getynge/piston,bvssvni/piston,placrosse/piston