It's a temporary change to account for your site being migrated to a new server cluster. Without that, your site would require downtime while DNS updated after the change. It will automatically disappear once DNS updates, which shouldn't take long.
Generally, it's best to not use the full domain in links to other pages on the same site. If you use relative links like "/discussion/123/discussion-title" then the link will work regardless of domain name.
Comments
It's a temporary change to account for your site being migrated to a new server cluster. Without that, your site would require downtime while DNS updated after the change. It will automatically disappear once DNS updates, which shouldn't take long.
Generally, it's best to not use the full domain in links to other pages on the same site. If you use relative links like "/discussion/123/discussion-title" then the link will work regardless of domain name.