cracked nether brick variant generation within Nether Fortress

During the Nether Update, the Nether fortress was kept the same. Cracked nether bricks were added during the nether update but you can only obtain them by crafting. Structures such as jungle temples have moss blocks to give that old ruin effect. The Nether fortress should generate with both cracked and normal nether bricks to really bring out the ancient site of the structure.