message: Fix exception in get_block
diff: @@ -202,7 +202,9 @@ def get_block(id):
  if isinstance(id, str):
  id = bytes(id, 'utf8')
  info = get_block_(id)
  + if info:
  return JsonStruct(info)
  + return None
  def get_account(name):
  if isinstance(name, str):
  