Make nagios_client service management EL6-friendly.
Make nagios_client service management EL6-friendly.

We'll use the proper EL6 service commands when nagios_client is on EL6.
Probably we should be using proper service-oriented Ansible modules here
but that will come later.

sadsfae/ansible-nagios,sadsfae/ansible-nagios,sadsfae/ansible-nagios