[Treeview Menu]: Fix childs behaviour when closing parent treeview menu.

build/js/Treeview.js

@@ -80,11 +80,10 @@ class Treeview {
     const collapsedEvent = $.Event(EVENT_COLLAPSED)
 
     parentLi.removeClass(`${CLASS_NAME_IS_OPENING} ${CLASS_NAME_OPEN}`)
-    parentLi.find(SELECTOR_LI).removeClass(`${CLASS_NAME_IS_OPENING} ${CLASS_NAME_OPEN}`)
     treeviewMenu.stop().slideUp(this._config.animationSpeed, () => {
       $(this._element).trigger(collapsedEvent)
       treeviewMenu.find(`${SELECTOR_OPEN} > ${SELECTOR_TREEVIEW_MENU}`).slideUp()
-      treeviewMenu.find(SELECTOR_OPEN).removeClass(CLASS_NAME_OPEN)
+      treeviewMenu.find(SELECTOR_OPEN).removeClass(`${CLASS_NAME_IS_OPENING} ${CLASS_NAME_OPEN}`)
     })
   }