Resolve #3487705 "Refactor banuserform"

Closes #3487705

src/Entity/Builder/PrivateMessageThreadViewBuilder.php

@@ -112,7 +112,7 @@ class PrivateMessageThreadViewBuilder extends EntityViewBuilder {
       $build['#suffix'] = '</div></div>';
     }
     else {
-      $build['#prefix'] = '<div id="private-message-thread-' . $entity->id() . '" class="' . implode(' ', $classes) . '" data-thread-id="' . $entity->id() . '" data-last-update="' . $entity->get('updated')->value . '">';
+      $build['#prefix'] = '<div class="' . implode(' ', $classes) . '" data-thread-id="' . $entity->id() . '" data-last-update="' . $entity->get('updated')->value . '">';
       $build['#suffix'] = '</div>';
     }