fix(Core): fix chests not despawning when opened in group (#5371)

src/server/game/Loot/LootMgr.h

@@ -109,6 +109,7 @@ enum LootSlotType
 class Player;
 class LootStore;
 class ConditionMgr;
+class GameObject;
 struct Loot;
 
 struct LootStoreItem
@@ -311,6 +312,7 @@ struct Loot
 
     // GUIDLow of container that holds this loot (item_instance.entry), set for items that can be looted
     uint32 containerId{0};
+    GameObject* sourceGameObject;
 
     Loot(uint32 _gold = 0) : gold(_gold) { }
     ~Loot() { clear(); }