this simple fix should fix the goal time violated issue (#882)

Co-authored-by: Lennart Nachtigall <lennart.nachtigall@sci-mo.de>
(cherry picked from commit 3f423ed)

ur_controllers/src/scaled_joint_trajectory_controller.cpp

@@ -168,7 +168,7 @@ controller_interface::return_type ScaledJointTrajectoryController::update(const
       // time_difference is
       // - negative until first point is reached
       // - counting from zero to time_from_start of next point
-      double time_difference = time.seconds() - segment_time_from_start.seconds();
+      const double time_difference = time_data.uptime.seconds() - segment_time_from_start.seconds();
       bool tolerance_violated_while_moving = false;
       bool outside_goal_tolerance = false;
       bool within_goal_time = true;