我想将版本 13.10 升级到 14.04。这是我得到的输出：
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/saucy-security/universe/binary-i386/Packages 403 Forbidden
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/saucy-security/multiverse/binary-i386/Packages 403 Forbidden
E: Some index files failed to download. They have been ignored, or old ones used instead.
我的 Ubuntu 版本是 13.10 Saucy。