Match X-Robots-Tag recommendation in Nextcloud docs

[jfredrickson]

Pull Request

Description of the change

The latest Nextcloud documentation suggests setting X-Robots-Tag to noindex, nofollow. This changes the nginx configuration to align with that recommendation.

More context: nextcloud/server#37357

Specifically, this explanation: nextcloud/server#37357 (comment)

Benefits

Prior to this change, someone who is following the Nextcloud documentation to set up their instance may set their nginx reverse proxy to add the X-Robots-Tag: noindex, nofollow header. Then their Nextcloud instance still generates the following warning even though they followed the documentation:

The "X-Robots-Tag" HTTP header is not set to "noindex, nofollow". This is a potential security or privacy risk, as it is recommended to adjust this setting accordingly.

This is because the Helm chart's included nginx instance still adds X-Robots-Tag: none.

Possible drawbacks

I'm unsure if older Nextcloud installations will then start to complain that the older recommendation of X-Robots-Tag: none isn't implemented.

Applicable issues

N/A

Additional information

N/A

Checklist

• DCO has been signed off on the commit.
• Chart version bumped in Chart.yaml according to semver.