[Bug] Resuming Session - loses Supervisor and Site

[philsturgeon]

We have to pop out of a session now and then for reasons like editing a photo, seeing how many are in the queue, maybe a hard exit if storage ran out, etc.

When we try to resume the session we have to pick supervisor and site again, which is a regression as it used to remember who you were. It's been broken for ages and we can cope but it's a little thing that keeps us out in the cold longer with cold hands wishing we were at the pub. 😆