remove trailing whitespaces in read_write_node.py
remove trailing whitespaces in read_write_node.py

ROBOTIS-GIT/DynamixelSDK,ROBOTIS-GIT/DynamixelSDK,ROBOTIS-GIT/DynamixelSDK,ROBOTIS-GIT/DynamixelSDK,ROBOTIS-GIT/DynamixelSDK,ROBOTIS-GIT/DynamixelSDK,ROBOTIS-GIT/DynamixelSDK