Player/Quest: Credit group for gameobject activation if they are in proximity.

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

@@ -1353,7 +1353,15 @@ void GameObject::Use(Unit* user)
                         break;
                 }
 
-                player->KillCreditGO(info->entry, GetGUID());
+                if (Group* group = player->GetGroup())
+                {
+                    for (GroupReference const* itr = group->GetFirstMember(); itr != nullptr; itr = itr->next())
+                        if (Player* member = itr->GetSource())
+                            if (member->IsAtGroupRewardDistance(this))
+                                member->KillCreditGO(info->entry, GetGUID());
+                }
+                else
+                    player->KillCreditGO(info->entry, GetGUID());
             }
 
             if (uint32 trapEntry = info->goober.linkedTrapId)