Attachment links in SD notification mails miss base.url

Links to attachments added to an SD issue, are missing the instances base.url effectively creating a non-existing link.

Step to reproduce, on a Service Desk enabled project:

• In the issue view, go to More Actions -> Attach Files
• Add a new attachment
• In the same dialog, embed the attachment, eg: [^attachment.ext]
• After receiving the notification, try to open the link to the attachment. You'll find that the attachment link is broken

Example 2:

• On an existing issue with attachment
• Go to More Actions -> Attach Files
• Embed the existing attachment in the comment field, eg: [^filename.ext]
• After receiving the notification, try to open the link to the attachment.

Conclusion: When we embed an attachment via the Attach Files dialogue, the link to the attachment in the JSD notification is broken.