[jsk_robot_startup/smach_mail] Remove unused module

Author: tkmtnt7000

jsk_robot_common/jsk_robot_startup/scripts/smach_to_mail.py

@@ -3,10 +3,8 @@
 import base64
 import cv2
 import datetime
-import imghdr
 import pickle
 import rospy
-import time
 import sys
 
 from cv_bridge import CvBridge