[qa] example_test.py failed

[maflcko]

There are occasional failures of example_test on travis, which are annoying but not critical.

It will timeout while waiting for an verack on the added p2p connection:

self.nodes[2].p2p.wait_for_verack()

The issue might be that we add a p2p connection in L134 and then start the network thread:

bitcoin/test/functional/example_test.py

Lines 134 to 139 in a892218

	# Create a P2P connection to one of the nodes
	self.nodes[0].add_p2p_connection(BaseNode())
	# Start up network handling in another thread. This needs to be called
	# after the P2P connections have been created.
	NetworkThread().start()

Afterward, we don't restart the network thread, but add yet another p2p connection:

bitcoin/test/functional/example_test.py

Lines 190 to 192 in a892218

	self.log.info("Add P2P connection to node2")
	self.nodes[2].add_p2p_connection(BaseNode())
	self.nodes[2].p2p.wait_for_verack()

I have slight doubt that this is expected to work.