Increase catapult and bolt shooter health by factor 2.5 and 2 (as rams have 4 times that health and still vanish quickly enough when encountering sword units).
Make catapults more affordable by reducing their stone cost from 350 to 250 per unit.

Differential Revision: https://code.wildfiregames.com/D102
Reviewed By: scythetwirler, fatherbushido