Bring the code in line with the documentation that claims the `[quota.default].TOTAL` option supports unit suffixes.
Resolvesforgejo/forgejo#8996
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/9252
Reviewed-by: Lucas <sclu1034@noreply.codeberg.org>
Reviewed-by: Gusted <gusted@noreply.codeberg.org>
Co-authored-by: Brook <brook@noreply.codeberg.org>
Co-committed-by: Brook <brook@noreply.codeberg.org>