pytest: make test_multirpc check that RPC commands complete.

This was hanging sometimes in travis, but actually checking the result
of the commands makes it *always* hang.  We remove the waitinvoice
which will not return.

ZmnSCPxj points out that this behavior, introduced in
ce0bd7abd3, is a regression: it would be
nice to be able to cancel a waitinvoice.  But that fix is more complex,
and will have to be another PR.

This test will now hang, but it's OK: we're about to fix it!

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

tests/test_misc.py

@@ -605,13 +605,14 @@ def test_multirpc(node_factory):
         b'{"id":5,"jsonrpc":"2.0","method":"listpeers","params":[]}',
         b'{"id":6,"jsonrpc":"2.0","method":"listpeers","params":[]}',
         b'{"method": "invoice", "params": [100, "foo", "foo"], "jsonrpc": "2.0", "id": 7 }',
-        b'{"method": "waitinvoice", "params": ["foo"], "jsonrpc" : "2.0", "id": 8 }',
+        # FIXME: b'{"method": "waitinvoice", "params": ["foo"], "jsonrpc" : "2.0", "id": 8 }',
         b'{"method": "delinvoice", "params": ["foo", "unpaid"], "jsonrpc" : "2.0", "id": 9 }',
     ]
 
     sock.sendall(b'\n'.join(commands))
 
-    l1.rpc._readobj(sock)
+    for i in commands:
+        l1.rpc._readobj(sock)
     sock.close()