Fix kubernetes autodiscovery

Change-Id: I78b2e5edd7f3ac5837e3ed801a3f0cc5d8a15cdf
diff --git a/kubernetes/meta/prometheus.yml b/kubernetes/meta/prometheus.yml
index df0ee76..f73bd29 100644
--- a/kubernetes/meta/prometheus.yml
+++ b/kubernetes/meta/prometheus.yml
@@ -13,7 +13,7 @@
   target:
     kubernetes:
       enabled: true
-      api_ip: ${_param:kubernetes_control_address}
+      api_ip: {{ pool.apiserver.host }}
       cert_name: prometheus-server.crt
       key_name: prometheus-server.key
     static: