/etc/default/krb5-admin-server: 'RUN_KADMIND=false' not possible anymore

[Giuseppe Mazza]

Dear All,

I want to install a new kerberos slave running on Ubuntu16.04.
I would like to prevent the service  krb5-admin-server running on the slave.

It seems to me that is not possible to set the variable 
'RUN_KADMIND=true' in /etc/default/krb5-admin-server anymore.

I wonder if you could advice about the best way to do it.

Kind regards,
  Giuseppe