Issue Description:

Adding the Advanced filter to a backpack makes the backpack non configurable.

What happens:

after adding the advanced filter to a backpack, you cannot shift-right-click the backpack anymore

What you expected to happen:

I expected to see a configurable filter list

Steps to reproduce (important):

1. created a new minecraft instance with forge 12.18.2.2107 and iron backpacks (only)
2. give self a diamond backpack and add advanced filter upgrade
3. shift-rightclick
   ...

Affected Versions (Do not use "latest"):

• IronBackpacks: 1.10.2-2.2.7
• Minecraft: 1.10.2
• Forge: forge 12.18.2.2107