don't cache vips_system()
don't cache vips_system()

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