Log Message:
xfce4-whiskermenu-plugin: update to 2.8.4

2.8.4
=====
- Fix menu not hiding in labwc.
- Fix GHashTable leak in Settings::load.
- Fix string leak in is_separator.
- Translation updates: Basque, Bulgarian, Chinese (China), Czech, Dutch,
  Estonian, French, Galician, Georgian, Indonesian, Polish, Russian, Slovak,
  Slovenian, Turkish.