Make second user admin

In seeds.rb we create the first user which is 'User deleted', so the first actual user which we need to become an admin is the second user of the database.

https://github.com/openSUSE/osem/issues/456
hmmm ? First user is the deleted user, second user is the first real user... (since this is before create, we check if there is already one user, the deleted user, and make the next one admin). 

(We should probably check if seeding has successfully taken place?)