Log Message:
Update sysutils/collectd to 5.6.2.
Most of the NetBSD specific patches were re-applied due to code
syntax changes.

Upstream changes in 5.6.2:
- collectd: A compile error on AIX has been fixed: "MSG_DONTWAIT" is not
  available on AIX.
- collectd: The capability checking has been rewritten to be more
  portable.
- collectd.conf(5): Various typos have been fixed.
- collectd-tg: Incorrect usage of "nanosleep()" has been fixed which
  caused the tool to sleep (almost) indefinitely.
- Build system: Detection of the Java environment has been made
  deterministic to allow for reproducible builds.
- Build system: Detection of the Lua headers has been improved.
- APC UPS plugin: Unavailable metrics are now skipped instead of
  reported as 0 (zero).
- Modbus plugin: Build issues on FreeBSD have been fixed.
- OpenVPN plugin: Gracefully handle empty configurations.
- PowerDNS plugin: The "recursor command" has been fixed so PowerDNS can
  correctly parse all requested fields.
- Write Graphite and AMQP plugins: A bug that could lead to a missing
  null-termination has been fixed.
- Write HTTP plugin: A logic error when checking the correctness of the
  data set has been fixed.
- Write Kafka plugin: The "Key Random" config option has been fixed.
- Write Kafka plugin: Support for librdkafka 0.9.0 has been added.
- Write Riemann plugin: Build issues on Solaris have been fixed.
- ZFS ARC plugin: A duplicate metric has been removed.