This commit updates the PowerDNS authoritative server to 4.9.17,
the latest release in the 4.9.x LTS branch.
This fixes several security issues, including but not limited to:
CVE-2026-33257, CVE-2026-33260, CVE-2026-33611, CVE-2026-33610,
CVE-2026-33609, CVE-2026-33608, CVE-2026-42002, CVE-2026-42001,
CVE-2026-42000, CVE-2026-41999, CVE-2026-42396, CVE-2026-42005,
CVE-2026-52682.