Fix first user creation modal

Current Situation:
When I spin up a brand new app (no users created yet) it sends me to a login page and asks for a username and password. That's confusing, because I don't have a user created yet.

Desired Situation:
App should check to see if there are users in the database when I go to /admin. If there are no users created yet, it should prompt me to create the first user.