fix: js error as guest on DiscussionListItem (#4056)

Author: imorland

framework/core/js/src/forum/components/DiscussionListItem.tsx

@@ -74,7 +74,7 @@ export default class DiscussionListItem<CustomAttrs extends IDiscussionListItemA
     const discussion = this.attrs.discussion;
     const controls = DiscussionControls.controls(discussion, this).toArray();
 
-    items.add('controls', this.controlsView(controls), 100);
+    !!controls.length && items.add('controls', this.controlsView(controls), 100);
     items.add('slidableUnderneath', this.slidableUnderneathView(), 90);
     items.add('content', this.contentView(), 80);
 
@@ -83,16 +83,14 @@ export default class DiscussionListItem<CustomAttrs extends IDiscussionListItemA
 
   controlsView(controls: Mithril.ChildArray): Mithril.Children {
     return (
-      !!controls.length && (
-        <Dropdown
-          icon="fas fa-ellipsis-v"
-          className="DiscussionListItem-controls"
-          buttonClassName="Button Button--icon Button--flat Slidable-underneath Slidable-underneath--right"
-          accessibleToggleLabel={app.translator.trans('core.forum.discussion_controls.toggle_dropdown_accessible_label')}
-        >
-          {controls}
-        </Dropdown>
-      )
+      <Dropdown
+        icon="fas fa-ellipsis-v"
+        className="DiscussionListItem-controls"
+        buttonClassName="Button Button--icon Button--flat Slidable-underneath Slidable-underneath--right"
+        accessibleToggleLabel={app.translator.trans('core.forum.discussion_controls.toggle_dropdown_accessible_label')}
+      >
+        {controls}
+      </Dropdown>
     );
   }