peer: save minimum possible depth for anchor.

We'll save this in the database so we know where to start the chain
from when we reload.

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

daemon/peer.c

@@ -2001,6 +2001,7 @@ static struct peer *new_peer(struct lightningd_state *dstate,
 	peer->local.commit = peer->remote.commit = NULL;
 	peer->local.staging_cstate = peer->remote.staging_cstate = NULL;
 
+	peer->anchor.min_depth = get_block_height(peer->dstate);
 	htlc_map_init(&peer->htlcs);
 	
 	/* FIXME: Attach IO logging for this peer. */

daemon/peer.h

@@ -131,6 +131,9 @@ struct peer {
 		u64 satoshis;
 		u8 *witnessscript;
 
+		/* Minimum possible depth for anchor */
+		unsigned int min_depth;
+
 		/* If we're creating anchor, this tells us where to source it */
 		struct anchor_input *input;