Schedule elasticsearch 5.x ports for removal.

As elasticsearch components of versions prior to 7.3.x are not
maintained any longer, schedule EOL'd elastic ports for removal at
31st of March 2021.

Life cycle explained: https://www.elastic.co/support/eol

Reviewed by: osa (mentor)
Approved by: osa (mentor)
Differential Revision: https://reviews.freebsd.org/D27811