Fix nagios hostgroups glob matching

The hostgroups and hosts matching pattern must be the same to avoid
not configured host(s) referenced into a hostgroup.

Change-Id: I9a258d6c30324876c0b5ee2cd8ff7961fca1f076
diff --git a/nagios/server/init.yml b/nagios/server/init.yml
index e495915..561aace 100644
--- a/nagios/server/init.yml
+++ b/nagios/server/init.yml
@@ -45,9 +45,9 @@
         grain_hostname: 'host'
         hostname_suffix: ${_param:stacklight_environment}
         hostgroups:
-          - target: '*'
+          - target: 'G@services:openssh'
             name: All
-            expr_from: glob
+            expr_from: compound
           - target: 'G@roles:nova.controller'
             expr_from: compound # the default
             name: Nova Controller