add_action('parse_request', 'redirectUppercase',0);
function redirectUppercase() {
if(preg_match('/[A-Z]/', $_SERVER['REQUEST_URI'])) {
//if(preg_match('/+/', $_SERVER['REQUEST_URI'])) {
wp_redirect( $current_url = (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] === 'on' ? "https" : "http") . '://'.$_SERVER['HTTP_HOST'].strtolower($_SERVER['REQUEST_URI']),301);
exit();
}
}