Fix possible crash double-clicking in modded inventories. Fixes #1274

The Bukkit inventory event checks for InventoryAction.COLLECT_TO_CURSOR
by examining the contents of the inventory, using IInventory getContents().
However, this method is added by CraftBukkit and therefore is not available
on modded inventories. Catch the AbstractMethodError and set to
InventoryAction.NOTHING with ClickType.DOUBLE_CLICK instead.