Doubled letter, one correct one incorrect, ignores incorrect letter

[shmaller]

e.g.:
Wordle: SWEEP
Guess: exxex
Result: ---O-

This should report: X--O-.

When the later letter is correct, we write - to the first position, but we should clear the second position from guess and answer and then check first one again.

[shmaller]

fixed by resetting guess_i after finding a correct doubled letter.