wallet: Remember scriptpubkey that we pass to onchaind on init

This is the scriptpubkey that onchaind spends all funds to, except for
the their_unilateral/to-us case, so we better recognize that address.

Signed-off-by: Christian Decker <decker.christian@gmail.com>

lightningd/peer_control.c

@@ -1434,6 +1434,7 @@ static enum watch_result funding_spent(struct peer *peer,
 		tal_free(tmpctx);
 		return DELETE_WATCH;
 	}
+	txfilter_add_scriptpubkey(peer->ld->owned_txfilter, scriptpubkey);
 
 	if (!bip32_pubkey(peer->ld->wallet->bip32_base, &ourkey, keyindex)) {
 		peer_internal_error(peer,