net/powerdns: Update to version 5.0.3

Changelogs for 5.0.x
5.0.3
Released: 20th of February 2026
This is release 5.0.3 of the Authoritative Server. It contains bug fixes only.

Please review the Upgrade Notes before upgrading from versions < 5.0.x.

Bug Fixes
fix stupid logic error in lmdb-write-update-notification=no
References: pull request 16878
Stricter timestamp checks
References: pull request 16876
Correctly compute public key exponent length when larger than 255.
References: pull request 16874
fix geoip_mmdb backend MMDB_open error handling
References: pull request 16685
more robustness in createReverse*
References: pull request 16683