routing+lnrpc+lncli: allow setting min htlc policy

routing/localchans/manager.go

@@ -160,6 +160,11 @@ func (r *Manager) updateEdge(chanPoint wire.OutPoint,
 		edge.MaxHTLC = amtMax
 	}
 
+	// If a new min htlc is specified, update the edge.
+	if newSchema.MinHTLC != nil {
+		edge.MinHTLC = *newSchema.MinHTLC
+	}
+
 	// If the MaxHtlc flag wasn't already set, we can set it now.
 	edge.MessageFlags |= lnwire.ChanUpdateOptionMaxHtlc
 

routing/router.go

@@ -224,6 +224,10 @@ type ChannelPolicy struct {
 	// MaxHTLC is the maximum HTLC size including fees we are allowed to
 	// forward over this channel.
 	MaxHTLC lnwire.MilliSatoshi
+
+	// MinHTLC is the minimum HTLC size including fees we are allowed to
+	// forward over this channel.
+	MinHTLC *lnwire.MilliSatoshi
 }
 
 // Config defines the configuration for the ChannelRouter. ALL elements within