update template ingressClassName to className (#1009)

bootstrap/templates/kubernetes/apps/networking/echo-server/app/helmrelease.yaml.j2

@@ -70,7 +70,7 @@ spec:
     ingress:
       main:
         enabled: true
-        ingressClassName: external
+        className: external
         annotations:
           external-dns.alpha.kubernetes.io/target: "external.${SECRET_DOMAIN}"
           hajimari.io/icon: video-input-antenna