Heatmap renders black squares now

[centennialwebmaster]

• Gitea version (or commit ref):
• Git version: commit 2949043
• Operating system: linux
• Database (use [x]):
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  • MySQL
  • MSSQL
  • SQLite
• Can you reproduce the bug at https://try.gitea.io:
  • https://try.gitea.io/
  • No
  • Not relevant
• Log gist:

Description

Heatmap is no longer using shaded colors. Heatmap squares are now black only.

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Screenshots

[tonivj5]

Ref #5401 (comment)