fix(Core): fix chests not despawning when opened in group (2) (#5387)

* fix(Core): fix chests not despawning when opened in group

* fix(Core): fix crashes in pr #5371

* Replaced nullptr checks

* Used if with initializer instead of separate scope

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

@@ -58,6 +58,7 @@ GameObject::GameObject() : WorldObject(false), MovableMapObject(),
     m_lootGenerationTime = 0;
 
     ResetLootMode(); // restore default loot mode
+    loot.sourceGameObject = this;
     m_stationaryPosition.Relocate(0.0f, 0.0f, 0.0f, 0.0f);
 }