message: Remove default cluster configuration.
  When this default cluster configuration is setup, user have to override complete first cluster. Eg have to set KAFKA_CLUSTERS_0_ZOOKEEPER to empty string to override default localhost.
diff: kafka:
  - clusters:
  - - name: local
  - bootstrapServers: localhost:9092
  - zookeeper: localhost:2181
  - schemaRegistry: http://localhost:8081
  admin-client-timeout: 5000
  zookeeper:
  connection-timeout: 1000
  