message: Use the new ChainspecLoader::after_upgrade method
diff: @@ -482,12 +482,7 @@ impl reactor::Reactor for Reactor {
  ));
  let execution_pre_state = match maybe_latest_block_header {
  - Some(latest_block_header)
  - if chainspec_loader
  - .initial_execution_pre_state()
  - .next_block_height()
  - <= latest_block_header.height() =>
  - {
  + Some(latest_block_header) if !chainspec_loader.after_upgrade() => {
  ExecutionPreState::from(&latest_block_header)
  }
  _ => chainspec_loader.initial_execution_pre_state(),
  