nagios: correct path for copying phx2 nagios svcs

The nagios playbook is failing because it can't find a bunch of service
files. The playbook refers to a path of 'nagios/services/phx2/' but the
path that exists in git is 'nagios/services/phx2_internal'.

This fixes the path reference so that the playbook should complete.

roles/nagios_server/tasks/main.yml

@@ -174,7 +174,7 @@
 
 ## Copy over the services
 - name: Copy /etc/nagios/services (PHX2 specific files)
-  copy: src=nagios/services/phx2/{{ item }} dest=/etc/nagios/services/{{ item }}
+  copy: src=nagios/services/phx2_internal/{{ item }} dest=/etc/nagios/services/{{ item }}
   with_items:
     - basset.cfg
     - certgetter.cfg