`gp await-port` doesn't work correctly when port is private

Bug description

While testing https://twitter.com/gtsiolis/status/1417927681946103821?s=20
(https://gitpod.io/#https://gitlab.com/gitpod-io/gitlab/)

I was seeing this message in terminal, and it took forever

Awaiting port 3000... ok
Waiting for GitLab at https://3000-yellow-guineafowl-avf4hmmy.ws-us11.gitpod.io ...................

Changing port 3000 from private to public - fixes it right away.

Steps to reproduce

1. Open https://gitpod.io/#https://gitlab.com/gitpod-io/gitlab/
2. Wait for this kind of message in terminal

Awaiting port 3000... ok
Waiting for GitLab at https://3000-yellow-guineafowl-avf4hmmy.ws-us11.gitpod.io ...................

1. Change port 3000 from private to public
2. Confirm that terminal stopped waiting

Expected behavior

gp await 3000 should work the same when ports are set to private or public.

Example repository

https://gitpod.io/#https://gitlab.com/gitpod-io/gitlab/

Anything else?

No response

Start with the gp await-port/gp await 3000 command and reproduce the behavior using the linked GitLab example repository. Compare private and public port handling; done means gp await 3000 stops waiting correctly for both visibility settings.