message: [c++ grpc] Fix clang warning
diff: @@ -23,7 +23,7 @@ namespace bond { namespace ext { namespace grpc
  template <typename... Service>
  void Add(std::unique_ptr<Service>... services)
  {
  - std::initializer_list<int>{ (Add(boost::none, std::move(services)), 0)... };
  + (void)std::initializer_list<int>{ (Add(boost::none, std::move(services)), 0)... };
  }
  template <typename Service>
  