- Also accept attachments of type Image
- Prefer the key "image" if it is set as the banner image (https://www.w3.org/TR/activitystreams-vocabulary/#dfn-object)
- solves #1399
Co-authored-by: Thomas Citharel <tcit@tcit.fr>
Signed-off-by: Thomas Citharel <tcit@tcit.fr>
