Quick start demo rosdep install recives an error

[Hensbag]

Hello there I'm using the latest version of the autoware and I get error.I have downloaded autoware first but I wanted to try awsim to learn further more about autoware.While trying to install rosdep from awsim quick start demo I received that error :
ERROR: Rosdep experienced an error: Multiple packages found with the same name "velodyne_msgs":

• sensor_component/external/nebula/nebula_messages/velodyne_msgs
• sensor_component/external/velodyne_vls/velodyne_msgs
  Please go to the rosdep page [1] and file a bug report with the stack trace below.
  [1] : http://www.ros.org/wiki/rosdep

rosdep version: 0.22.2

Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/rosdep2/main.py", line 146, in rosdep_main
exit_code = _rosdep_main(args)
File "/usr/lib/python3/dist-packages/rosdep2/main.py", line 446, in _rosdep_main
return _package_args_handler(command, parser, options, args)
File "/usr/lib/python3/dist-packages/rosdep2/main.py", line 501, in _package_args_handler
pkgs = find_catkin_packages_in(path, options.verbose)
File "/usr/lib/python3/dist-packages/rosdep2/catkin_packages.py", line 35, in find_catkin_packages_in
packages = find_packages(path)
File "/usr/lib/python3/dist-packages/catkin_pkg/packages.py", line 103, in find_packages
raise RuntimeError('\n'.join(duplicates))
RuntimeError: Multiple packages found with the same name "velodyne_msgs":

• sensor_component/external/nebula/nebula_messages/velodyne_msgs
• sensor_component/external/velodyne_vls/velodyne_msgs
  Shall I delete the velodyne_msgs from one of them , I wanted to ask first before take an action I have frightened to broke workspace.