DEV: Removed needless indirection

An artifact of when tagging was a plugin no doubt.

app/assets/javascripts/discourse/controllers/tags-show.js.es6

@@ -8,21 +8,10 @@ import {
 import BulkTopicSelection from "discourse/mixins/bulk-topic-selection";
 import {
   default as NavItem,
-  extraNavItemProperties,
   customNavItemHref
 } from "discourse/models/nav-item";
 import Category from "discourse/models/category";
 
-if (extraNavItemProperties) {
-  extraNavItemProperties(function(text, opts) {
-    if (opts && opts.tagId) {
-      return { tagId: opts.tagId };
-    } else {
-      return {};
-    }
-  });
-}
-
 if (customNavItemHref) {
   customNavItemHref(function(navItem) {
     if (navItem.get("tagId")) {

app/assets/javascripts/discourse/models/nav-item.js.es6

@@ -122,6 +122,9 @@ NavItem.reopenClass({
     if (opts.category) {
       args.category = opts.category;
     }
+    if (opts.tagId) {
+      args.tagId = opts.tagId;
+    }
     if (opts.persistedQueryParams) {
       args.persistedQueryParams = opts.persistedQueryParams;
     }