Replace a 5 second sleep with a poll in anaconda

[bsanders]

When running through the installer with a site.attrs and rolls.xml in packer, ludicrous does not start in time to respond to initial requests in anaconda. Putting a manual sleep solves the issue. This should be replaced with something that poll-retry-(gently?)fails in the same place. See commit 9b37901

Ludicrous has a 'running' endpoint that could work as the poll target.

[bsanders]

@mikebobadilla can you double check this endpoint exists and works?

[mikebobadilla]

exists and works

https://github.com/Teradata/stacki/blob/master/common/src/stack/ludicrous-speed/ludicrous-client.py#L194