🐛 Fixed visibility of the post history feature

We had side stepped the existing checks of lexical and the feature flag when
checking if a published post was sent as an email. This takes into account the
existing checks to make sure the feature isn't leaked without the flag

ghost/admin/app/components/gh-post-settings-menu.js

@@ -150,7 +150,7 @@ export default class GhPostSettingsMenu extends Component {
             && this.post.emailOnly === false;
 
         if (this.post.isPublished === true) {
-            showPostHistory = this.post.hasEmail === false;
+            return showPostHistory && this.post.hasEmail === false;
         }
 
         return showPostHistory;