Error on setting backpack item unbreakable

[Sumafu]

09:34:04 [INFO] Khyron93 issued server command: /backpack
09:34:04 [WARNING] Exception in thread "pool-3-thread-14"
09:34:04 [WARNING] org.apache.commons.lang.UnhandledException: Plugin ChestBackpack v1.1.2 generated an exception while executing task 4134
09:34:04     at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:56)
09:34:04     at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
09:34:04     at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
09:34:04     at java.lang.Thread.run(Unknown Source)
09:34:04 Caused by: java.lang.NoSuchMethodError: org.bukkit.inventory.meta.ItemMeta.spigot()Lorg/bukkit/inventory/meta/ItemMeta$Spigot;
09:34:04     at de.sumafu.ChestBackpack.main.Backpack.getBackpack(Backpack.java:34)
09:34:04     at de.sumafu.ChestBackpack.main.CommandBackpack.run(CommandBackpack.java:65)
09:34:04     at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftTask.run(CraftTask.java:53)
09:34:04     at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53)
09:34:04     ... 3 more​

[Sumafu]

Releas 1.1.3