Reduce Flame Tank damage from 90 -> 75

As mentioned earlier, the reduction of the flame tank cost from $800 to $600 made it a bit too powerful. Playtesting with damage reduced to this level seemed to be reasonable.

The reason for reducing the cost to $600 was that few people were playing with the flame tank, since it costed a lot more than other units like the light tank. It seemed to be too much of a specialist and the added construction time (and cost) didn't appear to be worth it to players. It also seemed that people were not interested in risking the unit in battlefield offensives due to its cost. Part of the changes to the unit (increased damage vs. light, heavier armor, lower cost) were to make it more accessible for use against light vehicles (such as artillery), which it can destroy quickly, but which often result in its own death. A lower cost made the unit more usable in most mixed forces.