message: [executor] reset txns to empty in reconfig suffix
  Closes:
  Approved by: zekun000
diff: @@ -675,7 +675,7 @@ impl<V: VMExecutor> BlockExecutor for Executor<V> {
  block: (HashValue, Vec<Transaction>),
  parent_block_id: HashValue,
  ) -> Result<StateComputeResult, Error> {
  - let (block_id, transactions) = block;
  + let (block_id, mut transactions) = block;
  // Reconfiguration rule - if a block is a child of pending reconfiguration, it needs to be empty
  // So we roll over the executed state until it's committed and we start new epoch.
  @@ -708,6 +708,9 @@ impl<V: VMExecutor> BlockExecutor for Executor<V> {
  parent_accu.num_leaves(),
  );
  + // Reset the reconfiguration suffix transactions to empty list.
  + transactions = vec![];
  +
  (output, state_compute_result)
  } else {
  debug!("Received block {:x} to execute.", block_id);
  