Option to enable Bcrypt encryption for rock admin passwords

[madprogramer]

Rock Admin Passwords are currently visible to sys-admins. Perhaps this is desirable if anyone forgets the password, but all the same admins have the write-access to replace the password.

That being said, Rock supports bcrypted passwords, so maybe it is good to have a variable which can encrypt pwds on any set-up where non-admins might also have access to rock files.

• https://rockdoc.obiba.org/en/latest/admin/configuration.html#users-configuration
• password_hash with BCrypt not working ansible/ansible#81357