AdHoc command AuthenticateUser requires 'username' field, but uses 'accountjid'
The stage info that is returned by AdHoc command AuthenticateUser lists two arguments that should be sent. One of them is called 'username'.
The implementation does never attempt to get data that's sent by that key. Instead, it uses 'accountjid'.
I've changed the staging info output to match the implementation. This way, code that now successfully makes use of the old implementation will continue to work.