webui: fix excessive registration of state change event listeners

`Facet` descendants don't have `container` attribute as opposite to
`facet.facet`. Therefore the registration will happen on every facet
visit.

Reviewed-By: Endi Sukma Dewata <edewata@redhat.com>

install/ui/src/freeipa/Application_controller.js

@@ -323,7 +323,7 @@ define([
             if (menu_item) this.menu.select(menu_item);
 
             // show facet
-            if (!facet.container) {
+            if (!facet.container_node) {
                 facet.container_node = container.widget.content_node;
                 on(facet, 'facet-state-change', lang.hitch(this, this.on_facet_state_changed));
             }