Customize: Trailingslash the home nav menu item URL in starter content.

This prevents an additional 301 redirect when clicking on the nav menu item, and it also prevents a scenario where the auth cookie may not be passed 
and cause an authentication error when navigating in the customizer.

Props dlh, swissspidy.
Fixes #40112.

Merges [40300] to the 4.7 branch.

Built from https://develop.svn.wordpress.org/branches/4.7@40338


git-svn-id: http://core.svn.wordpress.org/branches/4.7@40245 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/theme.php

@@ -1983,7 +1983,7 @@ function get_theme_starter_content() {
 			'link_home' => array(
 				'type' => 'custom',
 				'title' => _x( 'Home', 'Theme starter content' ),
-				'url' => home_url(),
+				'url' => home_url( '/' ),
 			),
 			'page_home' => array( // Deprecated in favor of home_link.
 				'type' => 'post_type',

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.7.4-alpha-40337';
+$wp_version = '4.7.4-alpha-40338';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.