rolled back prefab update logic, new one was very dangerous, if needed can be reproduced manually, just reconnect your instance when needed

Author: nicloay

Assets/UnitySpineImporter/Scripts/Editor/Util/SpineUtil.cs

@@ -42,14 +42,8 @@ public static void buildPrefab(GameObject gameObject, string directory, string n
 			UnityEngine.Object oldPrefab = AssetDatabase.LoadAssetAtPath( prefabPath, typeof(GameObject));
 			if (oldPrefab == null)
 				PrefabUtility.CreatePrefab(prefabPath, gameObject, ReplacePrefabOptions.ConnectToPrefab);
-			else {
-				UnityEngine.Object instance = PrefabUtility.InstantiatePrefab(oldPrefab);
-				instance.name = instance.name+"_copy";
-				PrefabUtility.DisconnectPrefabInstance(instance);
+			else 
 				PrefabUtility.ReplacePrefab(gameObject, oldPrefab, ReplacePrefabOptions.ReplaceNameBased);
-				PrefabUtility.ReplacePrefab(instance as GameObject, oldPrefab, ReplacePrefabOptions.ConnectToPrefab);
-				GameObject.DestroyImmediate(instance);
-			}
 		}
 
 		public static void builAvatarMask(GameObject gameObject, SpineData spineData, Animator animator, string directory, string name){