graphics/openjump: Update to 1.16 release rev.6669

This is the final release of the long lasting OJ v1.x series.

The next release will introduce backward incompatible changes
that'll initially break all unmodified extensions/plugins. So
enjoy this one and look forward to OJ2 developed in a Git-repo
using the latest locationtech JTS.

Changelog: https://sourceforge.net/projects/jump-pilot/files/OpenJUMP/1.16/

Approved by: tcberner (mentor)
Differential Revision: https://reviews.freebsd.org/D28643