Removed the trailing whitespace for lint

Signed-off-by: Pyo <[email protected]>

turtlebot3_cartographer/launch/cartographer.launch.py

@@ -23,7 +23,7 @@
 from launch.conditions import IfCondition
 from launch.launch_description_sources import PythonLaunchDescriptionSource
 from launch.substitutions import LaunchConfiguration
-from launch.substitutions import ThisLaunchFileDir 
+from launch.substitutions import ThisLaunchFileDir
 from launch_ros.actions import Node