ubuntu旧版本无法更新解决

因部分老版本已经停止更新和支持，所以源路径已经发生改变，应该使用以下的源:

 http://old-releases.ubuntu.com

deb http://old-releases.ubuntu.com/ubuntu/ karmic main restricted universe multiverse

deb http://old-releases.ubuntu.com/ubuntu/ karmic-security main restricted universe multiverse

deb http://old-releases.ubuntu.com/ubuntu/ karmic-updates main restricted universe multiverse

deb http://old-releases.ubuntu.com/ubuntu/ karmic-proposed main restricted universe multiverse

deb http://old-releases.ubuntu.com/ubuntu/ karmic-backports main restricted universe multiverse

deb-src http://old-releases.ubuntu.com/ubuntu/ karmic main restricted universe multiverse

deb-src http://old-releases.ubuntu.com/ubuntu/ karmic-security main restricted universe multiverse

deb-src http://old-releases.ubuntu.com/ubuntu/ karmic-updates main restricted universe multiverse

deb-src http://old-releases.ubuntu.com/ubuntu/ karmic-proposed main restricted universe multiverse

deb-src http://old-releases.ubuntu.com/ubuntu/ karmic-backports main restricted universe multiverse