message: [Storage] Remove unused dead_code annotation
  It is no longer needed.
diff: @@ -91,7 +91,6 @@ pub struct LibraDB {
  transaction_store: TransactionStore,
  state_store: StateStore,
  event_store: EventStore,
  - #[allow(dead_code)]
  system_store: SystemStore,
  pruner: Pruner,
  }
  