Add apply ping{4,6} to generic-host example config again.

Fixes #6056

etc/icinga2/conf.d/generic-host.conf

@@ -6,6 +6,24 @@ template Host "generic-host" {
   check_command = "hostalive"
 }
 
+apply Service "ping4" {
+  import "generic-service"
+
+  check_command = "ping4"
+
+  assign where "generic-host" in host.templates
+  ignore where !host.address
+}
+
+apply Service "ping6" {
+  import "generic-service"
+
+  check_command = "ping6"
+
+  assign where "generic-host" in host.templates
+  ignore where !host.address6
+}
+
 apply Notification "mail-icingaadmin" to Host {
   import "mail-host-notification"