Removes old decrypt placeholder

pisa-btc/pisa/tools.py

@@ -1,2 +0,0 @@
-def decrypt_tx(m, k, cypher):
-    return m

pisa-btc/pisa/watcher.py

@@ -1,6 +1,5 @@
 from queue import Queue
 from threading import Thread
-from pisa.tools import decrypt_tx
 from pisa.responder import Responder
 from pisa.zmq_subscriber import ZMQHandler
 from bitcoinrpc.authproxy import AuthServiceProxy, JSONRPCException