SPIGOT-4109: Wall skulls not dropping

nms-patches/PlayerInteractManager.patch

@@ -199,7 +199,7 @@
              Block block = iblockdata.getBlock();
  
 +            // CraftBukkit start - Special case skulls, their item data comes from a tile entity (Also check if block should drop items)
-+            if (iblockdata.getBlock() instanceof BlockSkull && !this.isCreative() && event.isDropItems()) {
++            if (iblockdata.getBlock() instanceof BlockSkullAbstract && !this.isCreative() && event.isDropItems()) {
 +                iblockdata.getBlock().dropNaturally(iblockdata, world, blockposition, 1.0F, 0);
 +                return this.c(blockposition);
 +            }