Docker instance - use port 80 for the Ziti edge

[qrkourier]

Some internet circuits can only egress to the most common ports, e.g., a restrictive corporate VPN allowing 53, 80, 443, 3389, etc., making it impossible to use Ziti's default edge ports 1280 and 3022.

Currently, Caddy uses 80 as an HTTP redirect server to 443, but we could reconfigure Caddy to stop listening on 80 so the port is available for Ziti. That's two of the three required TCP ports needed for a zrok instance, reducing the burden of finding an available port.

The HTTP redirect is nice but not essential, and 80 is among the most universally permitted destination ports, so it's of particular value as a reliable default.