message: fix build for pre-C++11 compatibility
diff: @@ -100,7 +100,8 @@ private:
  struct EnableIfHasNextVariant {};
  template<typename R>
  - struct EnableIfHasNextVariant<R, typename Void<typename ROSServiceServerOperationCallerWrapper<ROS_SERVICE_T, variant + 1>::ProxyOperationCallerType>::type> {
  + struct EnableIfHasNextVariant<R,
  + typename Void<typename ROSServiceServerOperationCallerWrapper<ROS_SERVICE_T, variant + 1>::ProxyOperationCallerType>::type> {
  typedef R type;
  };
  @@ -112,13 +113,13 @@ private:
  template<typename R>
  struct DisableIfHasNextVariant<R, typename EnableIfHasNextVariant<R>::type> {};
  - template<typename Dummy = int>
  - static typename EnableIfHasNextVariant<Ptr>::type tryNextVariant(RTT::OperationInterfacePart* operation) {
  + template<typename Dummy>
  + static typename EnableIfHasNextVariant<Ptr>::type tryNextVariant(RTT::OperationInterfacePart* operation, Dummy* = 0) {
  return ROSServiceServerOperationCaller<ROS_SERVICE_T, variant + 1>::connect(operation);
  }
  - template<typename Dummy = void>
  - static typename DisableIfHasNextVariant<Ptr>::type tryNextVariant(RTT::OperationInterfacePart* operation) {
  + template<typename Dummy>
  + static typename DisableIfHasNextVariant<Ptr>::type tryNextVariant(RTT::OperationInterfacePart* operation, Dummy* = 0) {
  return Ptr();
  }
  