message: Add log messages when upgrading/downgrading in Linear Chain Sync
diff: @@ -791,11 +791,25 @@ where
  .cmp(&block_to_execute.protocol_version())
  {
  Ordering::Less => {
  + warn!(
  + block_hash = %block_to_execute.hash(),
  + our_version = %self.protocol_version,
  + block_version = %block_to_execute.protocol_version(),
  + "attempting to execute a block with a newer protocol version;\
  + shutting down to upgrade"
  + );
  return effect_builder
  .immediately()
  .event(|_| Event::Shutdown(StopReason::ForUpgrade));
  }
  Ordering::Greater => {
  + warn!(
  + block_hash = %block_to_execute.hash(),
  + our_version = %self.protocol_version,
  + block_version = %block_to_execute.protocol_version(),
  + "attempting to execute a block with an older protocol version;\
  + shutting down to downgrade"
  + );
  return effect_builder
  .immediately()
  .event(|_| Event::Shutdown(StopReason::ForDowngrade));
  