[rtvs] Fixed extractor for Slovak television and radio

[jastrab]

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• Bug fix
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Description of your pull request and other information

I updated the obsolete RTVS extractor. Fix Television and Radio.

As of 05709d9:

• closes [rtvs] Fixed extractor #21570
• closes [rtvs] Fixed extractor for Slovak television and radio. #28992
• resolves RTVS.sk not working #26731
• resolves Broken site support for RTVS.sk #21549.

[dirkf]

With apologies, I've updated your PR to match the current STVR/RTVS sites.