message: [chain]fix test.
diff: @@ -66,7 +66,7 @@ async fn gen_master_chain(
  collection.get_master_chain_info(),
  storage.clone(),
  txpool.clone(),
  - collection,
  + Arc::downgrade(&collection),
  )
  .unwrap();
  let block_template = chain
  @@ -171,7 +171,7 @@ async fn test_chain_apply() -> Result<()> {
  startup_info.master.clone(),
  storage,
  txpool,
  - collection,
  + Arc::downgrade(&collection),
  )?;
  let header = block_chain.current_header();
  debug!("genesis header: {:?}", header);
  