今晚我将 Ubuntu 从 17.04 升级到 17.10，以修复更新计算机时出现的“zesty 错误”。升级计算机后，我仍然不断收到错误消息。
输出apt-get update（错误行）：
E: The repository 'http://security.ubuntu.com/ubuntu zesty-security Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://nl.archive.ubuntu.com/ubuntu zesty-updates Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://nl.archive.ubuntu.com/ubuntu zesty Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://nl.archive.ubuntu.com/ubuntu zesty-backports Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: GPG error: http://deb.playonlinux.com wheezy InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 73F0D6E88E3D6C3A
E: The repository 'http://deb.playonlinux.com wheezy InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
据我所知，zesty 不再受支持。这是否意味着我可以删除“软件和更新 --> 其他软件”中的所有 zesty 行？例如：其他软件
jowi@jowi:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 17.10
Release: 17.10
Codename: artful