net/bind916: Update to 9.16.17

Feature Changes:
- After the network manager was introduced to named to handle incoming traffic,
  it was discovered that recursive performance had degraded compared to
  previous BIND 9 versions. This has now been fixed by processing internal
  tasks inside network manager worker threads, preventing resource contention
  among two sets of threads.

- Zone dumping tasks are now run on separate asynchronous thread pools. This
  change prevents zone dumping from blocking network I/O.

- inline-signing was incorrectly described as being inherited from the
  options/view levels and was incorrectly accepted at those levels without
  effect. This has been fixed; named.conf files with inline-signing at those
  levels no longer load.

Full changelog:
https://bind9.readthedocs.io/en/v9_16/notes.html#notes-for-bind-9-16-17

(otis)