FIX: ensures group-navigation states changes when route changes (#8724)

app/assets/javascripts/discourse/controllers/group.js.es6

@@ -2,6 +2,8 @@ import EmberObject from "@ember/object";
 import { inject } from "@ember/controller";
 import Controller from "@ember/controller";
 import { default as discourseComputed } from "discourse-common/utils/decorators";
+import { inject as service } from "@ember/service";
+import { readOnly } from "@ember/object/computed";
 
 const Tab = EmberObject.extend({
   init() {
@@ -17,6 +19,8 @@ export default Controller.extend({
   counts: null,
   showing: "members",
   destroying: null,
+  router: service(),
+  currentPath: readOnly("router._router.currentPath"),
 
   @discourseComputed(
     "showMessages",

app/assets/javascripts/discourse/templates/group.hbs

@@ -56,7 +56,7 @@
 <div class="user-content-wrapper">
   <section class="user-primary-navigation">
     <div class="container">
-      {{group-navigation group=model currentPath=router._router.currentPath tabs=tabs}}
+      {{group-navigation group=model currentPath=currentPath tabs=tabs}}
     </div>
   </section>