DEV: Fix failing test with watched words

Follow up to: bb31e7f5b6

This commit fixes this failing test:

`Assertion Failed: it should escape watched words`

Now that we have a handlebars template we can us it for escaping because
it does that for us.

app/assets/javascripts/admin/components/admin-watched-word.js.es6

@@ -1,6 +1,5 @@
 import Component from "@ember/component";
 import { iconHTML } from "discourse-common/lib/icon-library";
-import { escapeExpression } from "discourse/lib/utilities";
 
 export default Component.extend({
   classNames: ["watched-word"],
@@ -9,7 +8,7 @@ export default Component.extend({
 
   init() {
     this._super(...arguments);
-    this.set("watchedWord", `${escapeExpression(this.get("word.word"))}`);
+    this.set("watchedWord", this.get("word.word"));
   },
 
   click() {