ipaddr filter was moved to ansible.utils collection

[vinjana]

The role does not work anymore with Ansible 2.5+ as is, because the ipaddr filter has been moved to ansible.utils.

There seems to be a way to kind of "import" collections, but it seems that this is only possible from within roles, not from external as would be required for using the role in an otherwise Ansible 2.5+ project.

Fixing this is simple, but that would make the role imcompatible with earlier versions.

Any ideas or suggestions how to make this backwards compatible?