added correct property for manualfocus sony
added correct property for manualfocus sony

should fix https://github.com/gphoto/gphoto2/issues/416

gphoto/libgphoto2,gphoto/libgphoto2,gphoto/libgphoto2,gphoto/libgphoto2,gphoto/libgphoto2,gphoto/libgphoto2