Fixed talismans give bug

eco-core/core-plugin/src/main/kotlin/com/willfp/talismans/talismans/Talisman.kt

@@ -31,7 +31,7 @@ class Talisman(
 
     val description = config.getFormattedStrings("description").map { Display.PREFIX + it }
 
-    val itemStack: ItemStack = run {
+    private val _itemStack: ItemStack = run {
         val item = Items.lookup(config.getString("item"))
         Validate.isTrue(item !is EmptyTestableItem, "Item specified in " + key.key + " is invalid!")
         TalismanUtils.registerTalismanMaterial(item.item.type)
@@ -44,6 +44,9 @@ class Talisman(
             .build()
     }
 
+    val itemStack: ItemStack
+        get() = _itemStack.clone()
+
     val craftable = config.getBool("craftable")
 
     val recipe: CraftingRecipe? = run {