Error when loading site related to cookies app or code that no longer exists

have been trying to figure out why my site is slow and noticed a piece of code in the waterfall on the front page it goes red and shows failed and can take up to 500 or 600ms, could anyone guide me of how to delete and or find this code

apps3.omegatheme.com/cookies-notification/client/save-cookies.php    (failed)   apps3.omegatheme.com

thanks for any input , I presume this is one of those types of things that here so much about being left over from old apps..