[jsk_recognition_msgs] Fix the error

error: Multiple top-level packages discovered in a flat-layout: ['srv', 'msg', 'action', 'sample'].                                                                                                                                                                                 To avoid accidental inclusion of unwanted files or directories,
setuptools will not proceed with this build.                                                                                                                                                                                                                                        If you are trying to create a single distribution with multiple packages                                                                  on purpose, you should not rely on automatic discovery.                                                                                   Instead, consider the following options:                                                                                                                                                                                                                                            1. set up custom discovery (`find` directive with `include` or `exclude`)                                                                 2. use a `src-layout`                                                                                                                     3. explicitly set `py_modules` or `packages` with a list of names

To find more information, look for "package discovery" on setuptools docs.                                                                CMake Error at catkin_generated/safe_execute_install.cmake:4 (message):                                                                                                                                                                                                               execute_process(/home/obinata/ros/ros_o_ws/build/jsk_recognition_msgs/catkin_generated/python_distutils_install.sh)                       returned error code
Call Stack (most recent call first):
cmake_install.cmake:152 (include)

jsk_recognition_msgs/CMakeLists.txt

@@ -2,9 +2,6 @@ cmake_minimum_required(VERSION 2.8.3)
 project(jsk_recognition_msgs)
 find_package(catkin REQUIRED
   std_msgs sensor_msgs geometry_msgs message_generation pcl_msgs jsk_footstep_msgs)
-if(NOT $ENV{ROS_DISTRO} STREQUAL "indigo") # on noetic it needs catkin_install_python to support Python3 and it does not work on indigo for some reason...
-  catkin_python_setup()
-endif()
 add_message_files(
   FILES
   Accuracy.msg