ALBO: remove unused ingressClass from controller CR

Author: alebedev87

modules/creating-instance-aws-load-balancer-controller.adoc

@@ -28,7 +28,7 @@ spec:
   additionalResourceTags: <4>
   - key: example.org/security-scope
     value: staging
-  ingressClass: cloud <5>
+  ingressClass: alb <5>
   config:
     replicas: 2 <6>
   enabledAddons: <7>