Bug: Cannot open image in card

Steps to reproduce the behavior

1. Go to Board
2. Select a card or create a new
3. Insert a screenshot or an image
4. Image is shown in the description but neither downloading, nor opening, nor saving is possible.

Expected behavior

In best case it would be possible to click on the image and it opens in fullscreen popup were the user can download or share.

Edition and Platform

• Edition: Personal Server / Mattermost Boards (plugin)
• Version: 7.11.14
• Browser and OS: Mattermost client, Chrome