Fix notes appearing unsaved after saving them.

Bug: creating a note then saving it doesn't remove the red border
indicating it's unsaved.

Broken by 8df1496 / PR #2729.

Ref: http://danbooru.donmai.us/forum_topics/13348.

app/controllers/notes_controller.rb

@@ -65,7 +65,7 @@ private
   end
 
   def create_params
-    params.require(:note).permit(:x, :y, :width, :height, :body, :post_id)
+    params.require(:note).permit(:x, :y, :width, :height, :body, :post_id, :html_id)
   end
 
   def pass_html_id