Revert [30032] so appropriate PHP warnings aren't masked.

Fixes #28743

Built from https://develop.svn.wordpress.org/trunk@30592


git-svn-id: http://core.svn.wordpress.org/trunk@30582 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/nav-menu-template.php

@@ -95,7 +95,7 @@ class Walker_Nav_Menu extends Walker {
 		 * @param array  $args    An array of {@see wp_nav_menu()} arguments.
 		 * @param int    $depth   Depth of menu item. Used for padding.
 		 */
-		$class_names = join( ' ', (array) apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item, $args, $depth ) );
+		$class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item, $args, $depth ) );
 		$class_names = $class_names ? ' class="' . esc_attr( $class_names ) . '"' : '';
 
 		/**

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.1-beta2-30591';
+$wp_version = '4.1-beta2-30592';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.