KafkaCluster validation fails when custom webhook port is provided

[balassai]

Describe the bug
KafkaCluster webhook is not accessible when custom webhook port is provided.
The validations fails because the webhook is not reachable.

Steps to reproduce the issue:
Set the webhook.serverPort in the chart's values yaml.

webhook:
  enabled: true
  serverPort: 8444
#  tls:
#    certDir: ""
  certs:
    generate: true
    secret: "kafka-operator-serving-cert"

Deploy the operator with helm.

helm install kafka charts/kafka-operator

Edit attempt to an existing KafkaCluster resource fails, because the webhook is unreachable.

k edit kafkacluster kafka -n kafka    
error: kafkaclusters.kafka.banzaicloud.io "kafka" could not be patched: Internal error occurred: failed calling webhook "kafkaclusters.kafka.banzaicloud.io": Post "[https://koperator-kafka-operator-operator.kafka.svc:443/validate-kafka-banzaicloud-io-v1beta1-kafkacluster?timeout=10s](https://koperator-kafka-operator-operator.kafka.svc/validate-kafka-banzaicloud-io-v1beta1-kafkacluster?timeout=10s)": dial tcp 10.254.29.128:443: connect: connection refused
You can run `kubectl replace -f /var/folders/8l/6jws9zmx1ng710v4v252b9jm0000gr/T/kubectl-edit-664393602.yaml` to try this update again.

Expected behavior
The webhook shall be reachable when custom webhook port is provided.

Additional context
version: 0.22

[pregnor]

Resolved by #896, thanks.