Airbnb should remove the review. The review includes the statement "the host is dishonest". As well as being potentially defamatory, this breaches Airbnb's policy that reviews should avoid "Profanity, name calling and assumptions about a person’s character or personality". You have grounds for having it removed. The issue then becomes whether Airbnb will also remove that guest's star ratings of your property. They should, but if not, then you should let the review stand. It reflects badly on the guest, not you.