Do not allow a zero max height in BiomeJungle

Fixes GH-592

Thanks to the forge team who noticed this issue long ago

scripts/importmcdev.sh

@@ -38,6 +38,7 @@ function import {
 import AxisAlignedBB
 import BaseBlockPosition
 import BiomeBase
+import BiomeJungle
 import BiomeMesa
 import BlockChest
 import BlockFalling