channeld: Pass through the agreed feerate_per_kw to channeld

We were erroneously using the fee_base which refers to the fees we
require for forwarding transactions instead of the on-chain fees.

lightningd/channel.h

@@ -125,7 +125,7 @@ static inline u16 to_self_delay(const struct channel *channel, enum side side)
  * @funding_txout: The commitment transaction output number.
  * @funding_satoshis: The commitment transaction amount.
  * @local_msatoshi: The amount for the local side (remainder goes to remote)
- * @feerate_per_kw: feerate per kiloweight (satoshis)
+ * @feerate_per_kw: feerate per kiloweight (satoshis) for the settlement transaction
  * @local: local channel configuration
  * @remote: remote channel configuration
  * @local_basepoints: local basepoints.

lightningd/channel/channel.c

@@ -1617,12 +1617,14 @@ static void init_channel(struct peer *peer)
 	bool reconnected;
 	u8 *funding_signed;
 	u8 *msg;
+	u32 feerate_per_kw;
 
 	msg = wire_sync_read(peer, REQ_FD);
 	if (!fromwire_channel_init(peer, msg, NULL,
 				   &funding_txid, &funding_txout,
 				   &funding_satoshi,
 				   &peer->conf[LOCAL], &peer->conf[REMOTE],
+				   &feerate_per_kw,
 				   &peer->their_commit_sig,
 				   &peer->pcs.cs,
 				   &funding_pubkey[REMOTE],
@@ -1689,7 +1691,7 @@ static void init_channel(struct peer *peer)
 	peer->channel = new_channel(peer, &funding_txid, funding_txout,
 				    funding_satoshi,
 				    local_msatoshi,
-				    peer->fee_base,
+				    feerate_per_kw,
 				    &peer->conf[LOCAL], &peer->conf[REMOTE],
 				    &points[LOCAL], &points[REMOTE],
 				    &funding_pubkey[LOCAL],

lightningd/channel/channel_wire.csv

@@ -27,6 +27,7 @@ channel_init,,funding_txout,2
 channel_init,,funding_satoshi,8
 channel_init,,our_config,struct channel_config
 channel_init,,their_config,struct channel_config
+channel_init,,feerate_per_kw,4
 channel_init,,first_commit_sig,secp256k1_ecdsa_signature
 channel_init,,crypto_state,struct crypto_state
 channel_init,,remote_fundingkey,33

lightningd/peer_control.c

@@ -1196,6 +1196,7 @@ static bool peer_start_channeld(struct peer *peer,
 				      peer->funding_satoshi,
 				      &peer->our_config,
 				      &peer->channel_info->their_config,
+				      peer->channel_info->feerate_per_kw,
 				      &peer->channel_info->commit_sig,
 				      cs,
 				      &peer->channel_info->remote_fundingkey,