Fix puzzle #26 (Mastermind) guess validator returning the incorrect value in some cases - if guessing a right number in the wrong place, and that number was present in all 2 other locations, it would erroneously result in a count of 2 "right number in the wrong place" in the return. E.g. if the secret is "2 3 3" a guess of "3 1 1" was returning "0 2" but should return "0 1", which is what it does now. (bug credit: MannyKlystron)