php notice empty loggedin cookie

A tiny issue when not supplying a logged in cookie.
We get PHP Warning: Cookie names must not be empty in [deleted]/wp-content/plugins/vcaching/vcaching.php on line 532

The code below could test if $cookie is set first:
531 $cookie = get_option($this->prefix . ‘cookie’);
532 setcookie($cookie, 1, time()+3600*24*100, COOKIEPATH, COOKIE_DOMAIN, false, true);