message: refactor: simplify `has()` function
diff: @@ -34,8 +34,7 @@ inline std::optional<V> mapFind(const frozen::map<K, V, N>& container, K key) {
  */
  template<typename Set, typename T>
  inline bool has(const Set& container, T key) {
  - const auto found = container.find(key);
  - return found != container.end();
  + return container.find(key) != container.end();
  }
  