Define default for startupProbe.initialDelaySeconds

[harmjanblok]

The https://github.com/sentry-kubernetes/charts/blob/develop/charts/clickhouse/README.md specifies a default value for clickhouse.startupProbe.initialDelaySeconds, but https://github.com/sentry-kubernetes/charts/blob/develop/charts/clickhouse/values.yaml#L145-L150 doesn't.

[patsevanton]

work:

k get pod -n test
NAME                   READY   STATUS    RESTARTS   AGE
clickhouse-0           1/1     Running   0          10m
clickhouse-1           1/1     Running   0          10m
clickhouse-2           1/1     Running   0          10m
clickhouse-replica-0   1/1     Running   0          10m
clickhouse-replica-1   1/1     Running   0          10m
clickhouse-replica-2   1/1     Running   0          10m

get initialDelaySeconds:

k get pod -n test clickhouse-0  -o yaml | grep startup -A 5
    startupProbe:
      failureThreshold: 60
      initialDelaySeconds: 5
      periodSeconds: 5
      successThreshold: 1
      tcpSocket: