fix variable that went missing

Author: Pidu2

charts/cert-manager-webhook-dnsimple/templates/rbac.yaml

@@ -70,7 +70,7 @@ rules:
     verbs:
       - 'create'
 ---
-apiVersion: {{ $RBACAPIVersion }}
+apiVersion: rbac.authorization.k8s.io/v1
 kind: ClusterRoleBinding
 metadata:
   name: {{ include "dnsimple-webhook.fullname" . }}:domain-solver