Fix python script errors

src/EnergyExtractionShakeBTS.py

 #!/usr/bin/python3
 #
 # 
-# 
+#   Apply delta delay on B to BTS extraction delay to perform energy shake on BTS and measure BPM difference on X position.
+#   To use in conjuction with sequencer device
 #
 from tango import *
 import PyTango
@@ -9,7 +10,6 @@ import tango
 import sys, os
 import time
 import numpy as np
-from math import sqrt
 
 
 def main():
@@ -60,3 +60,4 @@ def main():
            
 if __name__ == '__main__':
     main()
+