Bugfix: `dockerhost` as upstream didn't work
Bugfix: `dockerhost` as upstream didn't work

Because the latest Nginx image used a slimmed down version of Debian, `ip` command was not found.

SteveLTN/nginx-acme,SteveLTN/https-portal,SteveLTN/nginx-acme,SteveLTN/https-portal,SteveLTN/https-portal,SteveLTN/nginx-acme