removed unused ctor

Assets/Scenes/ImageTracking/Multi Prefab - Image Tracking/MultiTrackedImageInfoManager.cs

     [RequireComponent(typeof(ARTrackedImageManager))]
     public class MultiTrackedImageInfoManager : MonoBehaviour, ISerializationCallbackReceiver
     {
-        [Serializable]
+        [Serializable]
         struct NamedPrefab
         {
             // System.Guid isn't serializable, so we store the Guid as a string. At runtime, this is converted back to a System.Guid
 
             [SerializeField]
             public GameObject m_Prefab;
-
-            public NamedPrefab(XRReferenceImage image, GameObject prefab)
-            {
-                m_ImageGuid = image.guid.ToString();
-                m_Prefab = prefab;
-            }
 
             public NamedPrefab(Guid guid, GameObject prefab)
             {