Test utils: fix config overrides for private channels

Previously, this test util did not account for config overrides supplied at
node creation time. Uncovered because it caused test nodes to be unable to
forward over private channels created with this util because that is not the
default.

Author: valentinewallace

lightning/src/ln/functional_test_utils.rs

@@ -1512,7 +1512,7 @@ pub fn create_announced_chan_between_nodes_with_value<'a, 'b, 'c: 'd, 'd>(nodes:
 }
 
 pub fn create_unannounced_chan_between_nodes_with_value<'a, 'b, 'c, 'd>(nodes: &'a Vec<Node<'b, 'c, 'd>>, a: usize, b: usize, channel_value: u64, push_msat: u64) -> (msgs::ChannelReady, Transaction) {
-	let mut no_announce_cfg = test_default_channel_config();
+	let mut no_announce_cfg = nodes[a].node.get_current_default_configuration().clone();
 	no_announce_cfg.channel_handshake_config.announce_for_forwarding = false;
 	nodes[a].node.create_channel(nodes[b].node.get_our_node_id(), channel_value, push_msat, 42, None, Some(no_announce_cfg)).unwrap();
 	let open_channel = get_event_msg!(nodes[a], MessageSendEvent::SendOpenChannel, nodes[b].node.get_our_node_id());