oops another const
oops another const

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