• devel/gecode: Update from 5.0.0 to 5.1.0
• Changelog: http://www.gecode.org/doc-latest/reference/PageChange.html#SectionChanges_5_1_0

PR: 221083
Submitted by: Demetris Procopiou <dem.procopiou@gmail.com> (maintainer)
Approved by: tz (mentor)
Differential Revision: https://reviews.freebsd.org/D11781