replace evil pig spawn with spawn_specific, make them passive again

mobs/pig_evil.lua

 local pigdef = {
 	type = "monster",
-	passive = false,
+	passive = true,
 	reach = 3,
-	damage = 12,
+	damage = 6,
 	attack_type = "explode",
 	explosion_radius = 4,
 	hp_min = 62,

spawn.lua

@@ -42,7 +42,8 @@ end
 
 --mobs:register_spawn("dmobs:dragon", {"default:leaves","default:dirt_with_grass"}, 20, 10, 64000, 2, 31000)
 
-mobs:register_spawn("dmobs:pig_evil", {"group:leaves"}, 20, 10, 2000, 510, 2000)
+--name, nodes, neighbors, min_light, max_light, interval, chance, active_object_count, min_height, max_height
+mobs:spawn_specific("dmobs:pig_evil", {"group:leaves"}, "air", 10, 20, 1, 8000, 1, 510, 2000)
 
 if dmobs.dragons then
 	--mobs:register_spawn("dmobs:dragon2", {"default:pine_needles"}, 20, 10, 64000, 2, 31000)