Using barrier's as allowed blocks causes double prompts.

[wolfebersahd]

Mincraft 1.12.2
Spigot Server: Latest 1.12.2 build
PhatLoots: 4.2.3

Steps to reproduce:

1. Add barrier block to allowed block list.
2. Look at selected barrier block and link to sampleloot.
3. Loot barrier block.
4. Wait for 2-3 minutes for the loot cooldown to expire.
5. Attempt to loot barrier block again.

Bug: The "you must wait 4 hours to loot this again" message appears twice in the players chat window.

Probability (10/10)

Background information:
I have armorstands that have gear on them that i wanted players to be able to loot. I was unable to link them to PhatLoots, therefor I placed the armorstands inside the invisible barrier blocks and use them to link to the loot.