Fix BlockPhysicsEvent having incorrect changed type. Fixes BUKKIT-5063

This change updates the reference to the local variable representing the
block being checked when calling BlockPhysicsEvent.

src/main/java/net/minecraft/server/World.java

@@ -468,7 +468,7 @@ public abstract class World implements IBlockAccess {
                 // CraftBukkit start
                 CraftWorld world = ((WorldServer) this).getWorld();
                 if (world != null) {
-                    BlockPhysicsEvent event = new BlockPhysicsEvent(world.getBlockAt(i, j, k), l);
+                    BlockPhysicsEvent event = new BlockPhysicsEvent(world.getBlockAt(i, j, k), CraftMagicNumbers.getId(block));
                     this.getServer().getPluginManager().callEvent(event);
 
                     if (event.isCancelled()) {