SPIGOT-4507: BlockRedstoneEvent current flipped for levers

nms-patches/BlockLever.patch

@@ -13,7 +13,7 @@
              return true;
          } else {
 +            // CraftBukkit start - Interact Lever
-+            boolean powered = iblockdata.get(POWERED);
++            boolean powered = !flag; // Old powered state
 +            org.bukkit.block.Block block = world.getWorld().getBlockAt(blockposition.getX(), blockposition.getY(), blockposition.getZ());
 +            int old = (powered) ? 15 : 0;
 +            int current = (!powered) ? 15 : 0;