Bug 21149: Fix superlibrarian creation in onboarding

Bug 21149: Fix superlibrarian creation in onboarding

See bug 21087 for more details.

Test plan:
Drop your DB
Start the installation process
Use the onboarding process to install missing data
The superlibrarian created during this process should be created
sucessfully and allowed to login

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>