Describe the bug
When using the tank upgrade for the backpacks, you can duplicate fluids by using tanks that can be stacked.

To Reproduce
Steps to reproduce the behavior:

1. Add a tank upgrade to a backpack.
2. Fill a column with the fluid of your choice (lava for example)
3. Then, use a stackable tank, with 64 of them stacked, to get the fluid back (Seared Fluid Tanks from Tinker's Construct for example)
4. The 64 tanks will be filled. Therefore you will have multiplied your fluids by 64.

Expected behavior
It should only fill one tank.

Versions
Last version sophisticatedbackpacks-1.16.5-3.2.4.321.jar

Fixed in the latest version on curseforge - only allows one tank to go in either output/input slot