mailto links are not properly formed when using Confluence Page Gadget

Problem

• mailto links work fine when added to a Confluence page
  • aka user@asdf123.com will result in opening a mail client to send mail to user@asdf123.com
• using the Confluence Page Gadget to view this same page, the link will instead be directed to address domain.com

Expected Behaviour is that the link will also result in opening a mail client to send mail to user@asdf123.com

Steps to Reproduce

• Create a new page in Confluence
• Add a link to the page user@asdf123.com
• Save page, confirm the behaviour
• In JIRA, add the Confluence Page macro
• Once displayed, observe that clicking the link does not actually trigger the mail event

Viewing the link source, we see:

• In Confluence's page, the working link:

  <a href="mailto:user@asdf123.com" class="external-link" rel="nofollow">mailto:user@asdf123.com</a>
  

• In JIRA via the Confluence Gadget macro:

  <a href="http://confluence-base-url.commailto:user@asdf123.com" class="external-link" rel="nofollow" target="_blank" data-processed="true">mailto:user@asdf123.com</a>