funding: when crafting our ChannelUpdate use the remote party's minHTLC
funding: when crafting our ChannelUpdate use the remote party's minHTLC

In this commit, we implement a recent spec change that require nodes to
advertise the minHTLC of the remote node within their ChannelUpdate. We
do this as it will be the remote node which carries the HTLC towards
us, therefore we should advertise *their* minHTLC value.

LightningNetwork/lnd,LightningNetwork/lnd,aakselrod/lnd,aakselrod/lnd