Comment 1 for bug 1862109

Figured this out, it wasn't an old pip, but an old setuptools.

```
cd /var/lib/juju/agents/unit-docker-97/.venv/
$ sudo ./bin/pip3 install --upgrade setuptools
Collecting setuptools
  Downloading setuptools-46.0.0-py3-none-any.whl (582 kB)
     |████████████████████████████████| 582 kB 1.5 MB/s
Installing collected packages: setuptools
  Attempting uninstall: setuptools
    Found existing installation: setuptools 41.6.0
    Uninstalling setuptools-41.6.0:
      Successfully uninstalled setuptools-41.6.0
Successfully installed setuptools-46.0.0
$
```