Fix Arithmetic Error

[lukemango]

Description

We found this issue by accident, but it seems that if Slimefun's ticks are faster than expected, Tier 3 items such as Electric Ore Grinders will produce an ArithmeticException.

https://pastebin.com/ZGWDJyWn - the error from our fork, this small patch fixed it.

Proposed changes

Don't update the progress bar if the operation is already finished

Related Issues (if applicable)

Resolves #3538

Checklist

• I have fully tested the proposed changes and promise that they will not break everything into chaos.
• I have also tested the proposed changes in combination with various popular addons and can confirm my changes do not break them.
• I followed the existing code standards and didn't mess up the formatting.
• I did my best to add documentation to any public classes or methods I added.
• I have added Nonnull and Nullable annotations to my methods to indicate their behaviour for null values
• I added sufficient Unit Tests to cover my code.

[Sfiguz7]

It's likely Biscuit will want the update progress to be in an else block but I personally don't mind it. I will just approve and let him or Walshy decide if they want to suggest the change before merging

[lukemango]

yeah I mean I don't mind changing it if that's what's preferred :)

[TheBusyBiscuit]

I approve of this, I even checked the logic and made a truth table.
But as pointed out, style-wise an inclusive-if would be preferred and we generally like to keep a reference to the fixed issue so we can better track these things.

Otherwise, it looks good! Thanks!

[Sfiguz7]

LGTM