Fix image attachments on comments

[dotmacro]

Problem

On comments, image attachments are only shown as file names, and are listed twice:

The links in the first list return a 404 error.

Solution

1. No links should return 404.
2. If there's no reason for a duplicate attachment list, remove the duplicate.
3. If there's no reason to hide images, show them. (Images are properly shown in articles.)