Move `min_sharding_lookback` to the right place. (#5007)
Move `min_sharding_lookback` to the right place. (#5007)

- This configuration is actually inside the limits section
- We shouldn't change the CLI flag to something different to not break
  existing deployments
grafana/loki,grafana/loki,grafana/loki,grafana/loki,grafana/loki,grafana/loki