TrajectoryExecutionManager claims succesful execution while no ControllerManager is installed

[Simon Schmeisser]

I was trying to setup a minimal system and missed adding moveit-plugins. The following code would however still claim successful execution (status == moveit_controller_manager::ExecutionStatus::SUCCEEDED)

trajectory_execution_manager_->push(plan.trajectory_);
trajectory_execution_manager_->execute();
moveit_controller_manager::ExecutionStatus status = trajectory_execution_manager_->waitForExecution();

It appears I should check the return value of push (would have been false), but still I would expect it to fail later on as well?