Living: fixed cycle between armor inventory and holder not getting cleaned up on close

this was getting collected by the cycle GC, but it should have been dealt with properly like other inventories.

src/pocketmine/entity/Living.php

@@ -809,4 +809,14 @@ abstract class Living extends Entity implements Damageable{
 
 		$this->armorInventory->sendContents($player);
 	}
+
+	public function close(){
+		if(!$this->closed){
+			if($this->armorInventory !== null){
+				$this->armorInventory->removeAllViewers(true);
+				$this->armorInventory = null;
+			}
+			parent::close();
+		}
+	}
 }