Fix expandinventory not allowing to return to minimal inventory size

[skyleo]

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

Allow expandinventory to return to original inventory size (minimal one).

See:

TehAroil 𝐏𝐋𝐕𝐠𝐠 — 11/01/2024 02:34
>Have 100 Possession Limit
>expandinventory(10);
>Now 110
>expandinventory(-10);
>Refused
>expandinventory(-9);
>Now 101
expandinventory(-1);
>Refused
>Have 101 Possession Limit

Issues addressed: None?