added missing @var property types (reported by phpstan)

src/pocketmine/block/Leaves.php

@@ -39,6 +39,7 @@ class Leaves extends Transparent{
 	public const DARK_OAK = 1;
 
 	protected $id = self::LEAVES;
+	/** @var int */
 	protected $woodType = self::WOOD;
 
 	public function __construct(int $meta = 0){

src/pocketmine/block/Leaves2.php

@@ -29,6 +29,7 @@ use pocketmine\item\ItemFactory;
 class Leaves2 extends Leaves{
 
 	protected $id = self::LEAVES2;
+	/** @var int */
 	protected $woodType = self::WOOD2;
 
 	public function getName() : string{

src/pocketmine/block/Liquid.php

@@ -38,6 +38,7 @@ use function min;
 
 abstract class Liquid extends Transparent{
 
+	/** @var int */
 	public $adjacentSources = 0;
 
 	/** @var Vector3|null */