Removed unecessary import

mg_control/launch/launch.py

@@ -1,6 +1,5 @@
 from launch import LaunchDescription
 from launch.actions import DeclareLaunchArgument, RegisterEventHandler, TimerAction
-from launch.event_handlers import OnProcessStart
 from launch.substitutions import LaunchConfiguration, PathJoinSubstitution, PythonExpression 
 from launch_ros.actions import Node
 from launch_ros.substitutions import FindPackageShare