Fixing bug introduced in last commit

private_message.module

@@ -436,39 +436,6 @@ function private_message_help($route_name, RouteMatchInterface $route_match) {
   }
 }
 
-/**
- * Implements hook_preprocess_field().
- *
- * Adds a custom class to the field that can be targeted, as the default classes
- * may be altered in themes/templates, and therefore should not be depended
- * upon.
- */
-function private_message_preprocess_field__private_message_thread__private_messages(&$vars) {
-  foreach (array_keys($vars['items']) as $index) {
-    $vars['items'][$index]['attributes']->setAttribute('class', 'private-message-wrapper');
-  }
-}
-
-/**
- * Implements hook_preprocess_container().
- *
- * Adds a custom class to the containers that can be targeted, as the default
- * classes may be altered in themes/templates, and therefore should not be
- * depended upon.
- */
-function private_message_preprocess_container(&$vars) {
-  if (isset($vars['element']['#id'])) {
-    if (strpos('edit-members-wrapper', $vars['element']['#id']) === 0) {
-      // Add a custom class to the private message members widget container.
-      $vars['attributes']['class'][] = 'private_message_members_widget_default_wrapper';
-    }
-    elseif (strpos('edit-message-wrapper', $vars['element']['#id']) === 0) {
-      // Add a custom class to the private message message widget container.
-      $vars['attributes']['class'][] = 'private_message_message_widget_default_wrapper';
-    }
-  }
-}
-
 /**
  * Implements hook_message_view_alter().
  *