Log Message:
Update sysutils/beats to 5.4.1.

Affecting all Beats
- Fix importing the dashboards when the limit for max open files is
  too low.
- Fix console output.
- Binaries upgraded to Go 1.7.6 which contains security fixes.

Filebeat
- Fix issue that new prospector was not reloaded on conflict.
- Fix grok pattern in filebeat module system/auth without hostname.
- Fix the Mysql slowlog parsing of IP addresses.

Winlogbeat
- Add the ability to use LevelRaw if Level isn't populated in the
  event XML.