pdns was updated to 4.1.2.

Security fixes:

* Dnsreplay: bail out on a too small outgoing buffer (CVE-2018-1046 bsc#1092540)

Improvements:

* API: increase serial after dnssec related updates
* Auth: lower ‘packet too short’ loglevel
* Make check-zone error on rows that have content but shouldn’t
* Auth: avoid an isane amount of new backend connections during an axfr
* Report unparseable data in stoul invalid_argument exception
* Backport: recheck serial when axfr is done
* Backport: add tcp support for alias

Bug Fixes:

* Auth: allocate new statements after reconnecting to postgresql
* Auth-bindbackend: only compare ips in ismaster() (Kees Monshouwer)
* Rather than crash, sheepishly report no file/linenum
* Document undocumented config vars
* Backport #6276 (auth 4.1.x): prevent cname + other data with dnsupdate

Misc fixes:

* Move includes around to avoid boost L conflict
* Backport: update edns option code list
* Auth: link dnspcap2protobuf against librt when needed
* Fix a warning on botan >= 2.5.0
* Auth 4.1.x: unbreak build