Broken wiki preview

[luwol03]

• Gitea version (or commit ref): 50a9727
• Git version: 2.20.1
• Operating system: Debian buster
• Database (use [x]):
  • PostgreSQL
  • MySQL
  • MSSQL
  • SQLite
• Can you reproduce the bug at https://try.gitea.io:
  • Yes (provide example URL)
  • No
  • Not relevant
• Log gist:

Description

If I will link I picture in a wiki, witch I have pushed to the wiki repo, the preview is broken, like these screenshots.

Markdown code:

Broken Preview:

Wiki: