Comment email link is not complete

[terriko]

Describe the bug
When a comment email is sent, the link to the comment is /en/users-blog/postname#commentnumber instead of https://blogs.python-gsoc.org/en/users-blog/postname#commentnumber. A full link rather than just the path would make it easier for people to click on the link (assuming their mail client does that) or cut-paste it (if their mail client doesn't make the link clickable).

Thanks to Stefan for this bug report via email.