chore: update readme license

[operagxoksana]

Relevant issues

Contributor checklist

• Provide tests for the changes (unless documentation-only)
• Documented any new features, CLI switches, etc. (if applicable)
  • Server --help output
  • README.md
  • doc/http-server.1 (use the same format as other entries)
• The pull request is being made against the master branch

Maintainer checklist

• Assign a version triage tag
• Approve tests if applicable

[KernelDeimos]

Thanks. I'm not a legal expert but every team I've worked with updated the copyright number each year, so I assume this is fine. If anybody finds an issue with this please re-open and tag me so that I see it.