Email link gets parsed as relative link #485

<!-- Please don't delete this template or we'll close your issue -->

<!-- Before creating an issue please make sure you are using the latest version of Saber. -->

<!-- Issues which contain questions or support requests will be closed. -->

<!-- Please ask questions via following several ways. -->

<!-- https://chat.saber.land/ -->

<!-- https://stackoverflow.com/questions/ask?tags=saberjs -->

Bug report

Steps to reproduce

Insert a mailto: link in a markdown file, e.g.

Send me an [e-mail](mailto:some@email.com)

Repl: https://codesandbox.io/s/saber-email-link-qb07d

What is expected?

The rendered HTML link should be

Send me an <a href="mailto:some@email.com">e-mail</a>

What is actually happening?

The root domain is added before the link

Send me an <a href="https://current-domain.com/mailto:some@email.com">e-mail</a>

Other relevant information

• Result of running saber -v: 0.9.1
• Does this issue occur when all plugins are disabled? Yes