Buff the Obelisk of Nod's health and damage

Add a buff to increase the obelisk of Nod's health from 400 to 600 - allowing it to be as durable as the advanced guard towers currently are - and their Damage from 200 to 360, making them equal to the AGT in base damage and about 25% more effective against tanks vs. the AGT's 288 in 96 ROF ticks.