Dead link to Svalbard Treaty on Archive Program Website

There is a dead link on the [Archive Vault](https://archiveprogram.github.com/arctic-vault/) page of the Archive Program website.

The current link points to: https://www.loc.gov/law/help/us-treaties/bevans/m-ust000002-0269.pdf

I don't know what the correct link should be, but I located the treaty in the Library of Congress in [Treaties and Other International Agreements of the United States of America: Volume 2 (Multilateral treaties, 1918-1930)](https://www.loc.gov/item/lltreaties-ustbv002/)

Working link to the treaty page: https://tile.loc.gov/storage-services/service/ll/lltreaties//lltreaties-ustbv002/lltreaties-ustbv002.pdf#page=277

Please advise if there is a better place to post this.

Open the Archive Vault page and inspect the Svalbard Treaty link currently pointing to the dead loc.gov PDF. Compare it with the working Library of Congress treaty PDF link provided in the issue. Done means the page links to the working treaty and the link opens successfully.

索引モデルが issue の本文から書いたものです。