Make Nagios less chatty

Nagios uses Syslog but passive_checks and external_commands
are really too chatting since StackLight is intensively using them.

https://github.com/Mirantis/mk-lab-salt-model/pull/181
diff --git a/nagios/server/init.yml b/nagios/server/init.yml
index 49fae4d..a8da37f 100644
--- a/nagios/server/init.yml
+++ b/nagios/server/init.yml
@@ -20,6 +20,9 @@
       check_service_freshness: 1
       check_host_freshness: 0
       purge_distribution_config: true
+      log_external_commands: 0
+      log_passive_checks: 0
+      log_initial_states: 1
       ui:
         enabled: true
         port: ${_param:nagios_ui_port}