vaultwarden: add connector HTML location blocks to handle 2FA connector calls

[jdarras-ac]

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• I have read the contributing guideline and understand that I have made the correct modifications

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Description

This PR adds a dedicated location block at the end of both Vaultwarden sample configs for the 2FA *-connector.html files:

• location regex: ^(/vaultwarden)?/.*-connector.html$
• response headers cleared for this endpoint:
  • Content-Security-Policy
  • X-Frame-Options

The proxying behavior in this new block is needed to avoid strange issues in regards of using some 2FA options.

Benefits of this PR and context

This provides a targeted exception for connector HTML endpoints while keeping the existing routing/auth structure unchanged elsewhere.

How Has This Been Tested?

• Verified that headers from SWAG proxy.conf / ssl.conf (when enabled in the deployment) are present when loading regular Vaultwarden pages.
• Verified with browser DevTools that the two headers targeted by this PR are absent on *-connector.html responses:
  • Content-Security-Policy
  • X-Frame-Options
• Confirmed no error is reported in the Vaultwarden admin panel diagnostics after applying this config change.

Source / References

• https://github.com/linuxserver/reverse-proxy-confs/blob/master/.github/CONTRIBUTING.md
• Some Backend Admin fixes and updates dani-garcia/vaultwarden#5272