Configuration of additional or readded Whisker menus is not saved

I removed the Whisker Menu and then decided to add it back. Its plugin ID changed for something other than 1. Currently, its hard-coded to only pick up whiskermenu-1.rc:

whiskermenu_file = 'whiskermenu-1.rc'
whiskermenu_path = os.path.join(GLib.get_home_dir(), '.config/xfce4/panel/', whiskermenu_file)

which causes this problem.

I suggest two options:

1. Save all of the active instances, i.e. those that are set and appear in /plugins/plugin-N 'whiskermenu'
2. Save only the most recently added one (determined either by its date or ID)