As a user, I'm unable to export the mapping ${wiki:Description}

As a user, I'm unable to export the mapping

${wiki:Description}

on the body of Post Functions or Scheduled Reports when the Description contains images.
Steps to reproduce this error:

1. Go to an issue and add images to the description
2. Create a new Post Function Send Report
3. Edit the body email with the mapping {wiki:Description}
4. Execute the transition in order to perform the post function.

Please, check also the option Send Email on the Scheduled Report by doing the same steps explained above.