wp_die( sprintf( __( 'Warning! User %s cannot be deleted.' ), $delete_user->user_login ) );
if ( in_array( $delete_user->user_login, $site_admins ) )
wp_die( sprintf( __( 'Warning! User %s cannot be deleted.' ), $delete_user->user_login ) );
if ( in_array( $delete_user->user_login, $site_admins ) )