[Retros] one man PGs (typo correction)

[Noam Elkies]

I wrote:

> http://www.janko.at/Retros/d.php?ff=rnbqkbBr/Rpppp1pp/P3R1q1/K6Q/1P1P4/4BN2/2P4P/3N4
>
> SPG-22.0 (C-)
>
> Intended solution:
>
> 1 d4 f5  2 Kd2 f4  3 Kc3 f3  4 Kb4 fxe2  5 Nc3 e1Q
> 6 Bc4 Qxf2  7 Bxg8 Qxg2  8 Qh5+ Qg6  9 Nc3 Qf7  10 Re1 Qg6 [...]

Typo: 9 Nf3.