Edgecase handling for ObjectAssigner

com.cyan.playerobjectpool/UdonSharp/CyanPlayerObjectAssigner.cs

@@ -174,6 +174,11 @@ public GameObject _GetPlayerPooledObject(VRCPlayerApi player)
         [PublicAPI]
         public GameObject _GetPlayerPooledObjectById(int playerId)
         {
+            if (!_enabledAndInitialized)
+            {
+                return null;
+            }
+
             int index = _objectPool._GetPlayerPoolIndexById(playerId);
 
             if (index == -1)
@@ -776,4 +781,4 @@ private void _LogError(string message)
 
         #endregion
     }
-}
+}