close_tx: use version 2.

As per the pending spec change: the other implementations use version 2,
and the current best practice advice (from maaku) is to use the latest
defined tx version.

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

common/close_tx.c

@@ -24,13 +24,12 @@ struct bitcoin_tx *create_close_tx(const tal_t *ctx,
 	 *
 	 * Note that there are two possible variants for each node.
 	 *
-	 * * version: 1
+	 * * version: 2
 	 * * locktime: 0
 	 * * txin count: 1
 	 */
 	/* Now create close tx: one input, two outputs. */
 	tx = bitcoin_tx(ctx, 1, 2);
-	tx->version = 1;
 
 	/* Our input spends the anchor tx output. */
 	tx->input[0].txid = *anchor_txid;