tests: fix txn_clone.py (retry)

There was a stale .pyc file around from before the move. This should
catch all missing modules and finally fix the travis build.

qa/rpc-tests/txn_clone.py

@@ -10,7 +10,7 @@
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.authproxy import AuthServiceProxy, JSONRPCException
 from decimal import Decimal
-from util import *
+from test_framework.util import *
 import os
 import shutil