Only refund quest scroll to leader if quest was active

otherwise quest leader gets more quest scrolls than they had to begin with.
This PR combines the last two functions into one (with the above two deletions). `async.parallel` will then determine this function complete on `User.update(..., cb)` and ignore the rest of the code, and we'll lose the `done` function's error-handler for `group.save()`. 

Un-delete the above two lines if you could & push, then I'll merge