juju upgrade-controller with custom caas-image-repo failed

[Tu Pham]

Setting caas-image-repo=192.168.1.1:8000 causes juju upgrade-controller failed with error:

```
ERROR Get "https://registry.hub.docker.com/v1/repositories/192.168.1.1:8000/jujusolutions/jujud-operator/tags": dial tcp: lookup registry.hub.docker.com on 127.0.0.53:53: read udp 127.0.0.1:49299->127.0.0.53:53: i/o timeout.
```

This bug is caused by malformed registry URL generated by the ListOperatorImages function in the docker package.

[John A Meinel (jameinel)]

I know Kelvin was working on this earlier, but I thought it actually landed. Which version was this fixed in? Is it part of the other authentication work, so would all be part of 2.9.13?

[Yang Kelvin Liu (kelvin.liu)]

This should be part of the authentication work. You know, the whole authentication work is still work in process. The dockerhub is done, but we are still integrating other providers. So I keep these related bugs open for now.

[Yang Kelvin Liu (kelvin.liu)]

https://github.com/juju/juju/pull/13400
https://github.com/juju/juju/pull/13350
https://github.com/juju/juju/pull/13386
https://github.com/juju/juju/pull/13192
https://github.com/juju/juju/pull/13285
https://github.com/juju/juju/pull/13296
https://github.com/juju/juju/pull/13341
https://github.com/juju/juju/pull/13322
These PRs have been landed to 2.9 to fix this issue.