fix: do not set the host address

[sbruens]

This was a regression introduced in #192, which was rolled out in outline-server v1.10.0 released last week and caused issues for users using machines with IPv6 disabled: Jigsaw-Code/outline-server#1601.

I'm unable to reproduce the issue itself when IPv6 is disabled on my corp or DigitalOcean machines, but that may be specific to those machines.

[jyyi1]

LGTM. But we need to verify whether it will fix the issue. Probably we can also have some configuration that let the user explicitly specify the IP stack (v4 or v6).

[sbruens]

LGTM. But we need to verify whether it will fix the issue.

Agreed, though I'm still unable to reproduce this issue, on a host machine or in a Docker container. I had wanted to replicate this in the outline-server integration test, but to no avail. I propose merging this change and, as you suggested offline, creating a new canary release that we could ask affected folks to test.

Probably we can also have some configuration that let the user explicitly specify the IP stack (v4 or v6).

The new service config allows this now at the outline-ss-server layer; the new configuration allows a full address specification, instead of just a port:

outline-ss-server/cmd/outline-ss-server/config_example.yml

Line 20 in cb5965f

address: "[::]:9000"

But we don't yet support this at the outline-server/Manager layer. I agree it would be nice to explicitly specify the stack there, but I'm also not sure it's totally necessary.