Since it's just the throatlatch, I would likely buy a new, better quality replacement and keep it on hand until the one you're using now breaks. If it's been conditioned after it was already cracked, then there isn't much you can do other than just take good care of it from now on. It is weaker than it was, and if it was in a more vital area like the crown or the cheek, then I would say replace it immediately and don't use it again. However, with it being on a non-pressure bearing area, it may break tomorrow or it may break 3 years from now LOL. The good news is that if it does break while you're riding, it shouldn't pose any risk.