fix(tracker/gioui): changing a hex played the previous value

CHANGELOG.md

@@ -106,6 +106,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
   x87 stack.
 
 ### Fixed
+- When changing a nibble of a hexadecimal note, the note played was the note
+  before changing the nibble
 - Loading a preset did not update the IDs of the newly loaded instrument,
   causing ID collisions and sends target wrong units.
 - The x87 native filter unit was denormalizing and eating up a lot of CPU ([#68][i68])

tracker/gioui/note_editor.go

@@ -329,8 +329,8 @@ func (te *NoteEditor) command(t *Tracker, e key.Event) {
 	var n byte
 	if t.Model.Notes().Effect(te.scrollTable.Table.Cursor().X) {
 		if nibbleValue, err := strconv.ParseInt(string(e.Name), 16, 8); err == nil {
-			n = t.Model.Notes().Value(te.scrollTable.Table.Cursor())
 			t.Model.Notes().FillNibble(byte(nibbleValue), t.Model.Notes().LowNibble())
+			n = t.Model.Notes().Value(te.scrollTable.Table.Cursor())
 			goto validNote
 		}
 	} else {