Bump datatables.net-plugins from 2.1.7 to 2.2.1

Bumps [datatables.net-plugins](https://github.com/DataTables/Plugins) from 2.1.7 to 2.2.1.
- [Commits](https://github.com/DataTables/Plugins/commits/2.2.1

)

---
updated-dependencies:
- dependency-name: datatables.net-plugins
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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