Fix no member users created in demo

Actually, it turns out that, if you look at the list of users, the Member role users are assigned a Reviewer role, and therefore there are duplicate Reviewer role assigned users.

It happens when the $role_settings is passed by reference to the role create loop. It is treated as a reference going forward, and the next place to pick that up is when the users get created.

To fix, I just renamed the user loop to $user_role_settings.

Patch forthcoming.