Pocketmine-mp: cancelling EntityDamageEvent Doesn't cancel fall damage

[UnknownOre]

Issue description

• entity die when falling even if the damage event is cancelled
  

  Steps to reproduce the issue

1. make a zombie fall from a really high area

OS and versions

• PocketMine-MP:This server is running PocketMine-MP 3.8.1 for Minecraft: Bedrock Edition v1.11.0 (protocol version 354)
• PHP:7.2
• Server OS:Windows 10

Plugins

public function onDamage(EntityDamageEvent $event){
    if (!$event instanceof EntityDamageByEntityEvent) return;
    $victim = $event->getEntity();
    if ($victim instanceof Player or !$victim instanceof Living) return;
    $event->setCancelled(true);
}

Crashdump, backtrace or other files

[UnknownOre]

if (!$event instanceof EntityDamageByEntityEvent) return;

facepalm