set default empty message, See #11644

git-svn-id: http://svn.automattic.com/wordpress/trunk@12775 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/schema.php

@@ -622,6 +622,7 @@ function populate_roles_300() {
 function populate_network( $network_id = 1, $domain = '', $email = '', $site_name = '', $path = '/', $vhost = 'no' ) {
 	global $wpdb, $current_site, $wp_version, $wp_db_version, $wp_rewrite;
 
+	$msg = '';
 	//@todo: turn these checks into returned messages
 	if ( $domain == '' )
 		die( 'You must provide a domain name!' );