Hide Wordpress update message on production server.

functions.php

// Hide update nag on the production server

$production = 'http://PRODUCTIONURL.com';
$check_url = home_url();

function hideUpdateNag() {
    remove_action( 'admin_notices', 'update_nag', 3 );
}
if ( $production == $check_url ) {
    add_action('admin_menu','hideUpdateNag');
}