Revert "For HBP, we can use a sha1 digest- 2"

This reverts commit b2a2e91bdb.

bridge_master.py

@@ -40,6 +40,7 @@ import re
 import copy
 from setproctitle import setproctitle
 #from crccheck.crc import Crc32
+import hashlib
 
 # Twisted is pretty important, so I keep it separate
 from twisted.internet.protocol import Factory, Protocol