Comment 1 for bug 2064107

In controller logs I see:

```
machine-0: 12:09:34 DEBUG juju.worker.apicaller [19a84c] failed to connect
machine-0: 12:09:34 DEBUG juju.worker.dependency "api-caller" manifold worker stopped: [19a84c] "machine-0" cannot open api: unable to connect to API: dial tcp 127.0.0.1:17070: connect: connection refused
stack trace:
dial tcp 127.0.0.1:17070: connect: connection refused
github.com/juju/juju/api.gorillaDialWebsocket:672:
github.com/juju/juju/api.dialer.dial1:1092:
github.com/juju/juju/api.dialer.dial:1067: unable to connect to API
github.com/juju/juju/api.dialWebsocketMulti:963:
github.com/juju/juju/api.dialAPI:621:
github.com/juju/juju/api.Open:120:
github.com/juju/juju/internal/worker/apicaller.connectFallback:162:
github.com/juju/juju/internal/worker/apicaller.ScaryConnect:217:
github.com/juju/juju/cmd/jujud-controller/agent/machine.commonManifolds.Manifold.ManifoldConfig.startFunc.func44:99: [19a84c] "machine-0" cannot open api
machine-0: 12:09:34 ERROR juju.worker.dependency "api-caller" manifold worker returned unexpected error: [19a84c] "machine-0" cannot open api: unable to connect to API: dial tcp 127.0.0.1:17070: connect: connection refused
```

Which may (or may not) be relevant