message: FIX: Double ModelHandle registration bug
  The handle was registered to the model interface *inside* a for loop, which was
  registering it twice.
diff: @@ -203,12 +203,12 @@ void FrankaHWSim::initFrankaModelHandle(
  "' in the <transmission> tag cannot be found in the URDF");
  }
  }
  + }
  auto root =
  std::find_if(transmission.joints_.begin(), transmission.joints_.end(),
  [&](const transmission_interface::JointInfo& i) { return i.role_ == "root"; });
  if (root == transmission.joints_.end()) {
  - throw std::invalid_argument("Cannot create franka_hw/FrankaModelInterface for robot '" +
  - robot +
  + throw std::invalid_argument("Cannot create franka_hw/FrankaModelInterface for robot '" + robot +
  "_model' because no <joint> with <role>root</root> can be found "
  "in the <transmission>");
  }
  @@ -216,8 +216,7 @@ void FrankaHWSim::initFrankaModelHandle(
  std::find_if(transmission.joints_.begin(), transmission.joints_.end(),
  [&](const transmission_interface::JointInfo& i) { return i.role_ == "tip"; });
  if (tip == transmission.joints_.end()) {
  - throw std::invalid_argument("Cannot create franka_hw/FrankaModelInterface for robot '" +
  - robot +
  + throw std::invalid_argument("Cannot create franka_hw/FrankaModelInterface for robot '" + robot +
  "_model' because no <joint> with <role>tip</role> can be found "
  "in the <transmission>");
  }
  @@ -228,13 +227,12 @@ void FrankaHWSim::initFrankaModelHandle(
  this->model_ = std::make_unique<franka_gazebo::ModelKDL>(urdf, root_link, tip_link);
  } catch (const std::invalid_argument& e) {
  - throw std::invalid_argument("Cannot create franka_hw/FrankaModelInterface for robot '" +
  - robot + "_model'. " + e.what());
  + throw std::invalid_argument("Cannot create franka_hw/FrankaModelInterface for robot '" + robot +
  + "_model'. " + e.what());
  }
  this->fmi_.registerHandle(
  franka_hw::FrankaModelHandle(robot + "_model", *this->model_, this->robot_state_));
  }
  -}
  void FrankaHWSim::initServices(ros::NodeHandle& nh) {
  this->service_set_ee_ =
  