Allow a role to be an administrator

I think the feature you are trying to remove makes sense for this module. This module revokes some permissions from ever being assigned (I think? at least it used to) whereas the admin role concept grants all permissions to one role.

So I'm against this proposal on concept.

Preventing a role from not being able to be assigned the admin privilege does not limit it from not being able to be assigned permissions that can lead to security breaches. The administrator role, like any other permission has to be assigned with care, but removing it is not a solution.

The best solution, I think, would be to delegate the administrator privilege to that role, as proposed in the related issue 540008, and that only through this role, you have this privilege.