Revert "Reverses subtraction in character.cpp to correct skill rust calculation"

[Foxtrot-Uniform42]

Summary

SUMMARY: Bugfixes "Corrects skill rust calculation based on intelligence stat. Revert #46605"

Purpose of change

In 'new' rust system #37281 higher 'skill rust' value leads to lower skill rust calculation in game (e.g. skill rust 200% is better than 50%).

Describe the solution

Set intelligence back to increase skill rust value to 'Higher intelligence = slower skill rusts' behavior.

Describe alternatives you've considered

Please refer to #46789

Testing

• Skill rust 10%
• All skills set to 30
• Lost 12% after 24 hours
  
• Skill rust 180%
• All skills set to 30
• Lost 1% after 24 hours
  

[BrettDong]

It would be better if you write more specifically what bug you are addressing in the summary line, because that will be compiled into a change log.

[Zireael07]

Out of scope for this PR, but this means the display in character creation should make it clear that bigger % is better.

[Foxtrot-Uniform42]

Out of scope for this PR, but this means the display in character creation should make it clear that bigger % is better.

I'll make another PR to change skill rust naming

[ToxiClay]

Sorry about this, folks. I went forward with my PR assuming that the text was accurate.

[Foxtrot-Uniform42]

Sorry about this, folks. I went forward with my PR assuming that the text was accurate.

I should've tested skill rust behavior before creating issue in a first place anyway, so...

[ToxiClay]

Out of scope for this PR, but this means the display in character creation should make it clear that bigger % is better.

I'll make another PR to change skill rust naming

The next PR should also address variable naming. rust_rate() is part of what led me to my assumption regarding the underlying math.