Fix bug where SU status wouldn't stick on creation

What does this MR do and why?

Fixes bug where if a user's super user election was true it would not stick through the creation process. User's would have to go back in to edit the user in order to give them super user status.

Related to issue #58 (closed)

How to set up and validate locally

With Current Dev:

1. Go to user creation page
2. Add a user and give them super user perms **This will not stick though creation

With this branch:

1. Go to user creation page
2. Create a user and give them super user perms **This will now stick through creation.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• Have you checked this doesn't interfere/conflict/duplicate someone elses work?
• Have you fully tested your changes?
• Have you resolved any lint issues?
• Have you assigned a reviewer?
• Have you applied correct labels?