Security update for pdns

Open Source Vulnerabilities openSUSE-SU-2019:1921-1

This update for pdns fixes the following issues: Security issues fixed: - CVE-2019-10203: Updated PostgreSQL schema to address a possible denial of service by an authorized user by inserting a crafted record in a MASTER type zone under their control. (boo#1142810) - CVE-2019-10162: Fixed a denial of service but when authorized user to cause the server to exit by inserting a crafted record in a MASTER type zone under their control. (boo#1138582) - CVE-2019-10163: Fixed a denial of service of slave server when an authorized master server sends large number of NOTIFY messages. (boo#1138582) Non-security issues fixed: - Enabled the option to disable superslave support. - Fixed `pdnsutil b2b-migrate` to not lose NSEC3 settings. This update was imported from the openSUSE:Leap:15.1:Update update project.