Fix ellipses button on comment post

The subtree retainer should take revealContent into account, so that when revealContent is toggled, it redraws the post

js/src/forum/components/CommentPost.js

@@ -40,7 +40,8 @@ export default class CommentPost extends Post {
 
     this.subtree.check(
       () => this.cardVisible,
-      () => this.isEditing()
+      () => this.isEditing(),
+      () => this.revealContent
     );
   }