大家好，我在配置caddy的时候出现了报错，大家有人遇到过这种问题吗
Ubuntu 18.04.3；Caddy v1.0.4
`root@guocheng:# service caddy status
● caddy.service - Caddy HTTP/2 web server
Loaded: loaded (/etc/systemd/system/caddy.service; enabled; vendor preset: enabled)
Active: failed (Result: exit-code) since Wed 2020-01-08 15:25:09 CST; 5s ago
Docs: https://caddyserver.com/docs
Process: 9274 ExecStart=/usr/local/bin/caddy -log stdout -log-timestamps=false -agree=true -conf=/etc/caddy/Ca
Main PID: 9274 (code=exited, status=226/NAMESPACE)
Jan 08 15:25:09 guocheng systemd[1]: Started Caddy HTTP/2 web server.
Jan 08 15:25:09 guocheng systemd[9274]: caddy.service: Failed to set up mount namespacing: No such file or direc
Jan 08 15:25:09 guocheng systemd[9274]: caddy.service: Failed at step NAMESPACE spawning /usr/local/bin/caddy: N
Jan 08 15:25:09 guocheng systemd[1]: caddy.service: Main process exited, code=exited, status=226/NAMESPACE
Jan 08 15:25:09 guocheng systemd[1]: caddy.service: Failed with result 'exit-code'.`
