Fix vsync not being disabled by default in cocoa
Fix vsync not being disabled by default in cocoa

vberger/glutin,kornholi/glutin,bvssvni/glutin,servo/glutin,mitchmindtree/glutin,TimNN/glutin,christopheraugustus/glutin,tomaka/winit,paulrouget/glutin,Ms2ger/glutin,fkaa/glutin,mvdnes/glutin,mmatyas/glutin,retep998/glutin,mbrubeck/glutin,vvuk/glutin,robertknight/glutin,nox/glutin,notriddle/glutin,mneumann/glutin,tomaka/glutin,adambadawy/glutin,ecoal95/glutin,mbrubeck/glutin,nc4rrillo/glutin,ozkriff/glutin,tempbottle/glutin,Jayflux/glutin