Room configuration prints "saved" early.

[cburschka]

The interactive room configuration command prints "Room configuration saved." when the form opens, before anything has been saved.

[cburschka]

The problem is that we're attaching a .then() to the configure() call as though it returned a promise (just like /create), but it doesn't. The interactive configuration form can be submitted multiple times.

So the success/error must be attached to the submit() call instead, so it can run every time.