include-excerpt doesn't correctly show images with relative attachment references when including an excerpt from another page

[lamblinc]

Images are not displayed in include-excerpt macro when the image has a relative reference rather an absolute one

Steps to reproduce the problematic behavior:

1. Create A page with an Excerpt macro in it
2. Include an image in the macro, with a relative reference - for example copy-paste an image
3. Save the page
4. Create B page with an include-excerpt macro in it, make it display the excerpt in A page
5. the image is not rendered

Expected behavior
The image is displayed

Actual behavior
You only have the name of th image, and it's not displayed

Environment (please complete the following information):

• OS: NA
• Browser: Chromium / Edge
• XWiki version 16.10.2/16.10.8
• App version 1.26.19/1.26.20

Additional context
Add any other context about the problem here.