pdns: update to 4.9.7

[Habbie]

📦 Package Details

Maintainer: @
_{(You can find this by checking the history of the package Makefile.)}

Description:

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🧪 Run Testing Details

• OpenWrt Version:
• OpenWrt Target/Subtarget:
• OpenWrt Device:

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✅ Formalities

• I have reviewed the CONTRIBUTING.md file for detailed contributing guidelines.

If your PR contains a patch:

• It can be applied using git am
• It has been refreshed to avoid offsets, fuzzes, etc., using

  make package/<your-package>/refresh V=s

• It is structured in a way that it is potentially upstreamable
  _{(e.g., subject line, commit description, etc.)
  We must try to upstream patches to reduce maintenance burden.}