fix: bug regarding cookie/referer

[CW-B-W]

Problem

When cookie/referer are set at the same time, aria2 failed to parse the cookie/referer arguments, and the target cannot be downloaded.
If only cookie is set, aria2 can successfully download the target.

Description

Because

result[kebabCaseKey] = `${options[key]}`

joins the array element with ','

Adapt it to

result[kebabCaseKey] = options[key].join('\n')

works on my side

Related Issues

Checklist:

• Have you checked to ensure there aren't other open Pull Requests for the same update/change?
• Have you linted your code locally prior to submission?
• Have you successfully ran app with your changes locally?

[agalwood]

Thanks for your fix 👍