fixed small bug in nohalo level 2 (wrong pointer index)
fixed small bug in nohalo level 2 (wrong pointer index)

wishabi/libvips,mcanthony/libvips,wishabi/libvips,leiyangyou/libvips,lovell/libvips,lovell/libvips,wishabi/libvips,wishabi/libvips,jcupitt/libvips,lovell/libvips,mcanthony/libvips,jcupitt/libvips,jcupitt/libvips,mcanthony/libvips,leiyangyou/libvips,mcanthony/libvips,lovell/libvips,jcupitt/libvips,leiyangyou/libvips,leiyangyou/libvips