message: fix typo in transaction_meta comments
diff: @@ -18,7 +18,7 @@ impl From<BitVecSerde> for BitVec {
  pub struct TransactionMeta {
  block_number: u64,
  /// first bit indicate if transaction is a cellbase transaction
  - /// next bits indicate if transaction has deal cells
  + /// next bits indicate if transaction has dead cells
  #[serde(with = "BitVecSerde")]
  dead_cell: BitVec,
  }
  