Core/Objects: Eliminate unneccessary temporary objects and double map lookups when building SMSG_UPDATE_OBJECT

(cherry picked from commit 38a209276d9a6b3fb5e657711894a1b696933c59)

Author: Shauren

src/server/game/Entities/Object/Object.cpp

@@ -505,15 +505,7 @@ void Object::ClearUpdateMask(bool remove)
 
 void Object::BuildFieldsUpdate(Player* player, UpdateDataMapType& data_map) const
 {
-    UpdateDataMapType::iterator iter = data_map.find(player);
-
-    if (iter == data_map.end())
-    {
-        std::pair<UpdateDataMapType::iterator, bool> p = data_map.emplace(player, UpdateData());
-        ASSERT(p.second);
-        iter = p.first;
-    }
-
+    UpdateDataMapType::iterator iter = data_map.try_emplace(player).first;
     BuildValuesUpdateBlockForPlayer(&iter->second, iter->first);
 }