quickstart environment polling seems excessive

I have about 10-15 environments defined in my .yaml file. Some of them have old .jenv files laying about from previous versions of juju even. So I hit bug #1522238. However, I noticed that some of my more recent environments are behind VPNs, or with a non-public provider, etc.

Quickstart seems to have changed it's behavior to now poll all of the api endpoints which leads to a long waiting game (I gave up after 10-15 minutes of waiting) for environments that are immediately contactable and alive.

This strikes me as bad form since the quickstart command I'm running is targeting a specific environment (`juju env`) and doesn't need to interact with those other ones at all.

Also note, this environment polling takes a long time, especially considering I have some environments that are not up all the time, maybe I have to activate a VPN to get to it, for instance. Seems like a pretty significant problem to block on this.

    juju quickstart u/landscape/landscape-dense-maas -e atlas