The Decline link in the invitation email is not placed as expected

Steps to reproduce

1. Go to Administer Wiki > Users & Rights > Invitation and configure the SMTP settings (I've used a real Gmail account)
2. Go to Invitation.WebHome and type in a recipient email address, and a message
3. Click 'Send Mail' button
4. Observe the email received and the placement of 'Accept the invitation and join' and 'Decline' links

Expected results

The 'Accept the invitation and join' and 'Decline' links are placed one near another.

Actual results

The 'Decline' link is placed on the far right side of the email body content and it may even not be that noticeable by the users, please see the attached screenshot.