Fix data validation

  * Convert `int` from string to int.

EME-19

Change-Id: Ibe4194cad670ee2f975053ef09127bea55edae2a
diff --git a/maas/region/single.yml b/maas/region/single.yml
index 20779aa..3fdc105 100644
--- a/maas/region/single.yml
+++ b/maas/region/single.yml
@@ -36,7 +36,7 @@
         dnssec_validation: 'no'
         enable_third_party_drivers: true
         maas_name: mas01
-        active_discovery_interval: '600'
+        active_discovery_interval: 600
         ntp_external_only: true
         upstream_dns: ${_param:dns_server01}
         enable_http_proxy: false