Default values inconsistent with values schema

[WoutDev]

Since the latest release of the ClickHouse helm chart, the default values.yaml seems to be inconsistent with its schema, causing issues when deploying the chart.

Sample log:

  Warning  InstallFailed  3s  helm-controller  Helm install failed for release clickhouse/clickhouse with chart clickhouse@0.3.5: values don't meet the specifications of the schema(s) in the following chart(s):
clickhouse:
- at '/clickhouse/extraContainers': got array, want object
- at '/clickhouse/extraVolumes': got array, want object

Can be hot fixed by overwriting the extraContainers and extraVolumes values as follows:

  values:
    clickhouse:
      # ... other values
      extraContainers: {}
      extraVolumes: {}