ddns-scripts: fix updating IPv6 for netcup

[beedaddy]

Fixes #30387
Uses suggested fix from #30387 (comment)

📦 Package Details

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

Description:

Fixes #30387
Uses suggested fix from #30387 (comment)

🧪 Run Testing Details

• OpenWrt Version: 25.12.5
• OpenWrt Target/Subtarget:
• OpenWrt Device: GL.iNet Flint 2

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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.}

[openwrt]

Formality Check: Suggestions Available

We checked this pull request against the contribution guidelines. Here is what needs your attention:

⚠️ STYLISTIC WARNINGS & SUGGESTIONS

Package Release Audit:

• ⚠️ Content changed in these packages, but without a PKG_RELEASE or version bump:

  • net/ddns-scripts

  Increment PKG_RELEASE by 1 (or bump PKG_VERSION/PKG_SOURCE_DATE and reset PKG_RELEASE to 1) so users receive the update.

Do not increment release for minor changes. Cosmetic edits (e.g., typos in comments, copyright updates, formatting/whitespace), changing the package maintainer (PKG_MAINTAINER), or updating source download info (PKG_SOURCE_URL / PKG_HASH) do not require incrementing PKG_RELEASE.

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_{Something broken? Consider reporting an issue.
Running version 059e3de deployed on 2026-09-09 11:53:18 CEST}

[openwrt-ai]

Reviewed 1 new commit.

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Generated by Claude Code

[openwrt-ai]

Commit checks

• 4eb2e6f "ddns-scripts: apply suggestion from @openwrt-ai" — subject describes the review workflow, not the change. Say what it does (e.g. ddns-scripts: fix typo in netcup comment), or fold it into ac80481.
• f73c532 "ddns-scripts: apply suggestion from @openwrt-ai" — same; this one changes the record-match comparison to the new IP, which is the substance of ac80481 and belongs squashed into it rather than as a follow-up with an unrelated subject.

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Generated by Claude Code

[openwrt-ai]

This was the last consumer of REGISTERED_IP, so the guard at update_netcup_com.sh:46 now aborts on a variable the script no longer reads — and write_log 14 exit 1s the whole updater. That kills the very first IPv4 update on a fresh setup, where get_registered_ip returns 127 and leaves REGISTERED_IP empty. Drop that line.

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Generated by Claude Code