Make ur_controllers compileable on humble (#1207)

No += overload for Duration class on humble

ur_controllers/src/passthrough_trajectory_controller.cpp

@@ -44,6 +44,7 @@
 
 #include <controller_interface/controller_interface.hpp>
 #include <rclcpp/logging.hpp>
+#include <rclcpp/version.h>
 #include <builtin_interfaces/msg/duration.hpp>
 #include <lifecycle_msgs/msg/state.hpp>
 
@@ -327,8 +328,12 @@ controller_interface::return_type PassthroughTrajectoryController::update(const
         scaling_factor_ = scaling_state_interface_->get().get_value();
       }
 
+#if RCLCPP_VERSION_MAJOR >= 17
       active_trajectory_elapsed_time_ += period * scaling_factor_;
-
+#else
+      // This is kept for Humble compatibility
+      active_trajectory_elapsed_time_ = active_trajectory_elapsed_time_ + period * scaling_factor_;
+#endif
       // RCLCPP_INFO(get_node()->get_logger(), "Elapsed trajectory time: %f. Scaling factor: %f, period: %f",
       // active_trajectory_elapsed_time_.seconds(), scaling_factor_, period.seconds());