我正在学习一个旧教程，并通过 apt-get 安装了一个存储库（我认为就是这样）我不是 ubuntu 大师。原来那个 repo 不再存在，当我现在做一个 apt-get 更新时，我得到了这个：
W: Failed to fetch http://ppa.launchpad.net/colingille/freshlight/ubuntu/dists/wily/main/binary-i386/Packages 404 Not Found
我尝试了通常的
sudo rm /var/lib/apt/lists/* -vf
但没有运气。存储我自己添加的所有 repos 的列表在哪里？我该如何摆脱这个？
因此，由于工作中的一次“升级”，我们获得了新的VPN证书。它是自签名的，并且不再有效。这是系统日志：
openconnect[6002]: Connected to xxx:443
openconnect[6002]: SSL negotiation with xxx
openconnect[6002]: Server certificate verify failed: signer not found
openconnect[6002]: Connected to HTTPS on xxx
openconnect[6002]: Got CONNECT response: HTTP/1.1 200 OK
openconnect[6002]: CSTP connected. DPD 300, Keepalive 30
NetworkManager[1273]: Set up DTLS failed; using SSL instead
openconnect[6002]: Connected as 192.168.0.160, using SSL
openconnect[6002]: SIOCSIFMTU: Operation not permitted
NetworkManager[1273]: <info> [1537565026.6078] vpn-connection[0x55ab83c186c0,a0614dc2-f483-4dc9-87d4-7b9ac4169d31,"company",0]: VPN connection: (IP Config Get) reply received.
NetworkManager[1273]: <info> [1537565026.6106] vpn-connection[0x55ab83c186c0,a0614dc2-f483-4dc9-87d4-7b9ac4169d31,"company",7:(vpn0)]: VPN connection: (IP4 Config Get) reply received
NetworkManager[1273]: …