Merge #13965: tests: Fix extended functional tests fail

a9cf5c9 Import CInv from correct module (Chun Kuan Lee)

Pull request description:

  Fix extended tests fail

  https://travis-ci.org/bitcoin/bitcoin/builds/415574232

Tree-SHA512: 1dd8cd3854ddf4d8c2f4cb700c2b4d866c0890b57c2e0cf73a38b97fbbd13c8c6149a8914c9d03453b4625873241cc3d470f069dd1918cf360d10ad5d79d717f

Author: MarcoFalke

test/functional/example_test.py

@@ -15,8 +15,8 @@
 
 # Avoid wildcard * imports if possible
 from test_framework.blocktools import (create_block, create_coinbase)
+from test_framework.messages import CInv
 from test_framework.mininode import (
-    CInv,
     P2PInterface,
     mininode_lock,
     msg_block,