Remove hard-coded externaldns image versions

Related story: https://mirantis.jira.com/browse/PROD-22456

Change-Id: I7a0eb61cfc85ac71adc287bb9ee33e8c47cf9e97
diff --git a/classes/cluster/k8s-ha-calico/kubernetes/init.yml b/classes/cluster/k8s-ha-calico/kubernetes/init.yml
index b2a42fe..21432ae 100644
--- a/classes/cluster/k8s-ha-calico/kubernetes/init.yml
+++ b/classes/cluster/k8s-ha-calico/kubernetes/init.yml
@@ -77,7 +77,7 @@
     calico_private_netmask: 16
 
     # component docker images
-    kubernetes_externaldns_image: mirantis/external-dns:latest
+
     kubernetes_externaldns_provider: coredns
 
     kubernetes_metallb_addresses_pool: 172.16.10.60-172.16.10.80