Fix a regression in the mob drop rate calculation

[MishimaHaruna]

Pull Request Prelude

• I have followed proper Hercules code styling.
• I have read and understood the contribution guidelines before making this PR.
• I am aware that this PR may be closed if the above-mentioned criteria are not fulfilled.

Changes Proposed

The value was accidentally always overridden to be 900%. With the intent to cap to 90%, max(rate, 90000) erroneously used instead of min(rate, 9000).

Issues addressed: N/A (reported in discord)

[MrKeiKun]

@MishimaHaruna why change to min? that means even if @iteminfo calculates it to 100% it will just drop to 90%
since before my PR it was drop_rate = max(drop_rate, cap_value((int)(0.5 + drop_rate * (sd->sc.data[SC_OVERLAPEXPUP]->val2) / 100.), 0, 9000)); which is max...