Removing snow falls in the nether

- Placing a limitation at y = - 19600 for the snow falls, under they won't
  happend.
- Changing reload intervals for beginners' chests 1 and 2 (now 1h and
  40min)

mods/beginners_chest/init.lua

@@ -11,8 +11,7 @@
 chests = {
   [1] = {
     position = {x = 5, y = 40, z = -1},
-    interval_timer = 0,
-    interval_max = 7200,
+    interval_max = 3600,
 	stuff = {
 		[1] = "3d_armor:boots_steel",
 		[2] = "default:pick_stone",
@@ -22,7 +21,7 @@ chests = {
   },
   [2] = {
     position = {x = 34, y = 20, z = 101},
-    interval_max = 7200,
+    interval_max = 2400,
     stuff = {
 	[1] = "3d_armor:steel_chest",
 	[2] = "throwing:bow_stone",

mods/snowdrift/init.lua

@@ -48,7 +48,7 @@ minetest.register_globalstep(function(dtime)
 		return
 	end 
 	for _, player in ipairs(minetest.get_connected_players()) do
-		if math.random() > PPPCHA then
+		if math.random() > PPPCHA or player:getpos().y < -19600 then
 			return
 		end
 		local ppos = player:getpos()