Issue description:

Block tassating in world when breaking an bus

What happens:

I broke a export bus and crashed my client

What you expected to happen:

The bus breaks and gives back its item

Steps to reproduce:

1. place a bus connected to a conduit.
2. break bus

...

Version (Make sure you are on the latest version before reporting):

• Minecraft: 1.10.2
• Forge: 2139
• Refined Storage: 1.2.4

Does this issue occur on a server? [yes/no]
Yes

If a (crash)log is relevant for this issue, link it here:

http://pastebin.com/5YqdsxBS