databases/influxdb: Improve syslog logging title

This changes the log entries from "daemon[PID]: logmesage" to
"influxd[PID]: logmessage". While here, remove trailing spaces.

Approved by: 0mp (mentor)
Pull Request: https://github.com/freebsd/freebsd-ports/pull/121
Differential Revision: https://reviews.freebsd.org/D33907