Remove custom modification to wgRCMaxAge

[physikerwelt]

Currently, we face issues that sometimes take a long time to write in the recent changes table. While large table sizes are not a problem in general, 37M rows seems a bit large for an RC table.

Issue https://phabricator.wikimedia.org/T360410

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• [ ] Conceptual Review (Logic etc...)
• [ ] Code Review (Review your implementation)
• [ ] Checkout (Test changes locally)

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