pytest: make sure receiving peer's openingd is ready.

There's now a potential race: the source peer connect returns, but in
destination peer the master hasn't read the connect message from
connectd, so the peer isn't in listpeers yet.

(Previously the connection stayed in connectd, so there was no such
window).

This is an occasional issue in a few places.

Note that we take the opportunity to speed up test_disconnectpeer too
while we're there.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

tests/test_closing.py

@@ -1063,6 +1063,7 @@ def test_permfail_htlc_out(node_factory, bitcoind, executor):
     l2 = node_factory.get_node(disconnect=disconnects)
 
     l1.rpc.connect(l2.info['id'], 'localhost', l2.port)
+    l2.daemon.wait_for_log('openingd-{} chan #1: Handed peer, entering loop'.format(l1.info['id']))
     l2.fund_channel(l1, 10**6)
 
     # This will fail at l2's end.