3 fold repetition scoring issue

[maksimKorzh]

Pedro Castro (@pedrox) has kindly pointed out (on YouTube) where the bug was:

I didn't increment repetition index before making move from the UCI command, so literally didn't track history positions at all.
I didn't know how/why to do that until now. With this fix now everything is working.
So initially my question was wrong in terms of not being to the point.

Anyway, thanks for discussion and sharing drawing FENs. I'll test my engine with them.