Zerg: exclude queens from attack group

[alkurbatov]

Usually queens are not used for attack purposes especially at the early stage of the game because of quite slow move speed. The bot shouldn't count queens when he checks attack conditions neither include queens into attack group.

However some rare strategies exists which uses large number of queens at the battleground. Dunno should it be supported or not.

[davechurchill]

Good point, I will make this change, thank you