Add a `private` field to `WP_Plugin_Install_List_Table`, `$error`.

See #30891.

Built from https://develop.svn.wordpress.org/trunk@31164


git-svn-id: http://core.svn.wordpress.org/trunk@31145 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/class-wp-plugin-install-list-table.php

@@ -13,6 +13,8 @@ class WP_Plugin_Install_List_Table extends WP_List_Table {
 	public $orderby = null;
 	public $groups = array();
 
+	private $error;
+
 	public function ajax_user_can() {
 		return current_user_can('install_plugins');
 	}

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.2-alpha-31163';
+$wp_version = '4.2-alpha-31164';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.