Your HTML includes a canonical link to a different site, which is most likely why HN updated the link. Canonical links are used to allow search engines and other services to figure out that two different URLs are actually the same page, so I think HN did the right thing. Other services will do the same thing either via canonical links, or open graph tags.
You probably want to remove/update your page to point to the right site.
As to why this is even there, probably bad copy/paste, or you might wanna check your hosting provider/software for issues.
`<link rel="canonical" href="http://www.briiant.com/">`