ItemDropCooldown

If more than 5 items are dropped in 1 second by default, the item will not be allowed to drop for 5 seconds.

config.yml

Set display messages, time to count item drops, etc.

CheckSecond: Time to measure player item drops
MaxDropItem: Maximum value that a player can drop items
BlockSecond: Time to disable item drops if the player drops more items than the "MaxDropItem" value

BlockMessage: display message