sysutils/elephant: Update to 2.18.1
BITWARDEN option has been added. It is disabled by default because
rbw, one of the runtime dependencies, is not in the ports tree yet.
Changelog:
- https://github.com/abenz1267/elephant/releases/tag/v2.18.0
- https://github.com/abenz1267/elephant/releases/tag/v2.18.1
Reported by: GitHub (watch releases)