message: [state sync] reduce error verbosity
  currently state sync prints full stack trace whenever routine error occurs
  it polluts log. This diff reduces verbosity
  Closes:
  Approved by: andll
diff: @@ -162,12 +162,12 @@ impl<T: ExecutorProxyTrait> SyncCoordinator<T> {
  StateSynchronizerMsg_oneof::ChunkRequest(request) => {
  let known_version = request.known_version;
  if let Err(err) = self.process_chunk_request(peer_id, request).await {
  - error!("[state sync] failed to serve chunk request to {} with known version {}: {:?}", peer_id, known_version, err);
  + error!("[state sync] failed to serve chunk request to {} with known version {}: {}", peer_id, known_version, err);
  }
  }
  StateSynchronizerMsg_oneof::ChunkResponse(response) => {
  if let Err(err) = self.process_chunk_response(&peer_id, response).await {
  - error!("[state sync] failed to process chunk response from {}: {:?}", peer_id, err);
  + error!("[state sync] failed to process chunk response from {}: {}", peer_id, err);
  counters::OP_COUNTERS.inc(&format!("{}.{}", counters::APPLY_CHUNK_FAILURE, peer_id));
  } else {
  self.peer_manager.update_score(&peer_id, PeerScoreUpdateType::Success);
  @@ -179,7 +179,7 @@ impl<T: ExecutorProxyTrait> SyncCoordinator<T> {
  _ => {}
  }
  },
  - Err(err) => { error!("[state sync] network error {:?}", err); },
  + Err(err) => { error!("[state sync] network error {}", err); },
  }
  },
  _ = interval.select_next_some() => {
  @@ -238,7 +238,7 @@ impl<T: ExecutorProxyTrait> SyncCoordinator<T> {
  }
  }
  if let Err(err) = self.check_subscriptions().await {
  - error!("[state sync] failed to check subscriptions: {:?}", err);
  + error!("[state sync] failed to check subscriptions: {}", err);
  }
  }
  let sync_request_complete = self.sync_request.as_ref().map_or(false, |sync_req| {
  @@ -276,7 +276,7 @@ impl<T: ExecutorProxyTrait> SyncCoordinator<T> {
  || request.limit > self.config.max_chunk_limit
  {
  return Err(format_err!(
  - "[state sync] timeout: {:?}, chunk limit: {:?}, but timeout must not exceed {:?} ms, and chunk limit must not exceed {:?}",
  + "[state sync] timeout: {}, chunk limit: {}, but timeout must not exceed {} ms, and chunk limit must not exceed {}",
  request.timeout,
  request.limit,
  self.config.max_timeout_ms,
  @@ -295,7 +295,7 @@ impl<T: ExecutorProxyTrait> SyncCoordinator<T> {
  _ => latest_ledger_info.clone(),
  };
  - debug!("[state sync] chunk request: peer_id: {:?}, known_version: {}, latest_ledger_info: {}, target: {}", peer_id, request.known_version, latest_ledger_info.ledger_info().version(), target.ledger_info().version());
  + debug!("[state sync] chunk request: peer_id: {}, known_version: {}, latest_ledger_info: {}, target: {}", peer_id, request.known_version, latest_ledger_info.ledger_info().version(), target.ledger_info().version());
  // if upstream synchronizer doesn't have new data and request timeout is set
  // add peer request into subscription queue
  @@ -478,7 +478,7 @@ impl<T: ExecutorProxyTrait> SyncCoordinator<T> {
  }
  };
  debug!(
  - "[state sync] request next chunk. peer_id: {:?}, known_version: {}, timeout: {}",
  + "[state sync] request next chunk. peer_id: {}, known_version: {}, timeout: {}",
  peer_id,
  self.known_version + offset,
  timeout
  @@ -539,7 +539,7 @@ impl<T: ExecutorProxyTrait> SyncCoordinator<T> {
  }
  while let Some(res) = futures.next().await {
  if let Err(err) = res {
  - error!("[state sync] failed to notify subscriber {:?}", err);
  + error!("[state sync] failed to notify subscriber {}", err);
  }
  }
  Ok(())
  