Repeated "https://bitbucket.org/https://bitbucket.org" in the accept link if user is sent an invitation via email that's in plain text (BB-15602)

Repeated "https://bitbucket.orghttps://bitbucket.org" in plain text email of an invite:

MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit

You have been invited by xxxxx to become a contributor to xxx/xxxx on bitbucket.org.

Accept your invitation by visiting:

_https://bitbucket.orghttps://bitbucket.org/invitations/repository/xxxxx_

This invitation will expire in 30 days.

Cheers,
The Bitbucket Team

Workaround: Manually paste the invite link without it being repeated.