message: tools: support PX4 v1.11 SITL API
  This has changed slightly requiring the world as one of the arguments
  now.
diff: @@ -10,6 +10,11 @@ fi
  sitl_model=$1
  echo "SITL model: $sitl_model"
  +if [ "$PX4_VERSION" = "v1.11" ]; then
  + sitl_world="empty"
  + echo "SITL world: $sitl_world"
  +fi
  +
  set -e
  # This script spawns the Gazebo PX4 software in the loop (SITL) simulation.
  @@ -55,13 +60,24 @@ pushd .
  cd $px4_firmware_dir/build/px4_sitl_default/tmp/rootfs
  # And run
  +if [ "$PX4_VERSION" = "v1.11" ]; then
  $px4_firmware_dir/Tools/sitl_run.sh \
  $px4_firmware_dir/build/px4_sitl_default/bin/px4 \
  none \
  gazebo \
  $sitl_model \
  + $sitl_world \
  $px4_firmware_dir \
  $px4_firmware_dir/build/px4_sitl_default &
  +else
  + $px4_firmware_dir/Tools/sitl_run.sh \
  + $px4_firmware_dir/build/px4_sitl_default/bin/px4 \
  + none \
  + gazebo \
  + $sitl_model \
  + $px4_firmware_dir \
  + $px4_firmware_dir/build/px4_sitl_default &
  +fi
  # Go back to dir where we started
  popd
  