Collectd role : deletion of collectd_plugin_exec variable

This variable had to be activated only if collectd_plugin_exec_ifq_drops or
collectd_plugin_exec_dns_stats was also activated, for some configuration to be
taken into account. I changed the role so that the configuration is
automatically taken into account if one of these two variables is activated.

roles/collectd/defaults/main.yml

@@ -10,7 +10,6 @@ collectd_interval: "300"
 
 # exec plugin
 
-collectd_plugin_exec: false  # Set to true only if one of the exec plugins below is also set to true
 collectd_plugin_exec_interval: "{{ collectd_interval }}"
 collectd_plugin_exec_ifq_drops: false
 collectd_plugin_exec_dns_stats: false  # Based on unbound

roles/collectd/tasks/main.yml

@@ -24,7 +24,7 @@
   file:
     path: /usr/local/share/collectd/scripts
     state: directory
-  when: collectd_plugin_exec
+  when: collectd_plugin_exec_ifq_drops or collectd_plugin_exec_dns_stats
   tags:
     - collectd
 

roles/collectd/templates/collectd.conf.j2

@@ -6,7 +6,7 @@ LoadPlugin syslog
   LogLevel warning
 </Plugin>
 
-{% if collectd_plugin_exec is sameas true %}
+{% if (collectd_plugin_exec_ifq_drops is sameas true) or (collectd_plugin_exec_dns_stats is sameas true) %}
 <LoadPlugin exec>
   Interval {{ collectd_plugin_exec_interval }}
 </LoadPlugin>