Core/Objects: ported Heartbeat implementation fron master branch

src/server/game/Entities/GameObject/GameObject.cpp

@@ -827,7 +827,7 @@ bool GameObject::Create(ObjectGuid::LowType guidlow, uint32 name_id, Map* map, P
 
 void GameObject::Update(uint32 diff)
 {
-    m_Events.Update(diff);
+    WorldObject::Update(diff);
 
     if (AI())
         AI()->UpdateAI(diff);