My mint has small, yellowish spots on the top surface, at the tips of some of the leaves. The leaves also smell slightly off, in what can only be described as minty + wet-dog smell. The leaves never turn brown, or fall off, or get any worse than the few spots at the tips. Doesn't quite look like the mint rust that my google searches suggest, nor do I see any spider mites, which was the other suggestion. Wondering if it could be a water/sun/soil issue. Please help, it's nearly mojito season!