message: Fix compilation error after merge, minor updates.
diff: @@ -193,11 +193,6 @@ impl LedgerService {
  }
  pub fn build_pool_restart(&self, identifier: &str, action: &str, datetime: Option<&str>) -> Result<String, CommonError> {
  - let datetime = match datetime{
  - Some(_) => datetime.map(|result| result.to_string()),
  - None => None
  - };
  -
  if action != "start" && action != "cancel" {
  return Err(CommonError::InvalidStructure(format!("Invalid action: {}", action)));
  }
  @@ -207,9 +202,9 @@ impl LedgerService {
  }
  - let operation = PoolRestartOperation::new(action, datetime);
  + let operation = PoolRestartOperation::new(action, datetime.map(String::from));
  - Request::build_request(identifier.to_string(), operation)
  + Request::build_request(identifier, operation)
  .map_err(|err| CommonError::InvalidState(format!("Invalid pool_restart request json: {:?}", err)))
  }
  