Reduce Flamethrower speed to match rifle infantry

Given that Flamethrowers are quite powerful and tough (90 HP), I don't see why it makes sense to also have them be super fast. It seems they should walk at normal speed, especially given how much of a threat to buildings they are.

Reducing their speed will give Grenadiers the distinction of being a fast infantry unit.

If you think this hurts them too much, then their range should be increased, not their speed.