fix for new ubuntu
fix for new ubuntu

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