channeld: get htlc_maximum_msat from lightningd.

We used to calculate it ourselves.  Unfortunately this needs to
be done in several places, since new_channel() isn't used to fully
create a channel in the case of dual funding :(

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

lightningd/channel_control.c

@@ -702,6 +702,7 @@ void peer_start_channeld(struct channel *channel,
 				       channel->opener,
 				       channel->feerate_base,
 				       channel->feerate_ppm,
+				       channel->htlc_maximum_msat,
 				       channel->our_msat,
 				       &channel->local_basepoints,
 				       &channel->local_funding_pubkey,