lnwire: add todo for changing to SatPerKWeight for fee rates

lnwire/update_fee.go

@@ -1,6 +1,8 @@
 package lnwire
 
-import "io"
+import (
+	"io"
+)
 
 // UpdateFee is the message the channel initiator sends to the other peer if
 // the channel commitment fee needs to be updated.
@@ -10,6 +12,9 @@ type UpdateFee struct {
 
 	// FeePerKw is the fee-per-kw on commit transactions that the sender of
 	// this message wants to use for this channel.
+	//
+	// TODO(halseth): make SatPerKWeight when fee estimation is moved to
+	// own package. Currently this will cause an import cycle.
 	FeePerKw uint32
 }