Relay reuse with new domain

[jchiarulli]

Look into what happens if a relay implementation is reused with a new domain

[jchiarulli]

Currently, the previously created /var/www/<domain> directory will still exist for each relay implementation after setting a new domain for a previously set up relay implementation

The files being served by nginx will use the new /var/www/<domain> directory

The previously created /etc/letsencrypt directories and files will also still exist for the previously set up relay implementation

The previously created /etc/letsencrypt directories and files can be deleted using, e.g., the command certbot delete --cert-name NAME if desired

For now, we'll leave these previously created directories and files since they don't conflict when using a new domain