Mobs that are more than 10 levels lower or higher than the player give incorrect xp

Either we need to modify this equation, or just make these mobs give 0xp.

server/components/stats.js

if (Math.abs(levelDelta) <= 10)
	amount = ~~(((sourceLevel + levelDelta) * 10) * Math.pow(1 - (Math.abs(levelDelta) / 10), 2) * mult);