message: fixed result_gtest_checkers
diff: @@ -37,7 +37,7 @@ namespace framework {
  -> decltype(getMessage(std::declval<V>())) {
  using iroha::operator|;
  return iroha::expected::resultToOptionalValue(r) |
  - [](const auto v) { return getMessage(v); };
  + [](const auto &v) { return getMessage(v); };
  }
  template <typename E>
  @@ -51,7 +51,7 @@ namespace framework {
  -> decltype(getMessage(std::declval<E>())) {
  using iroha::operator|;
  return iroha::expected::resultToOptionalError(r) |
  - [](const auto e) { return getMessage(e); };
  + [](const auto &e) { return getMessage(e); };
  }
  template <typename V>
  