net/krakend-ce: Update 2.11.2 => 2.12.0

Changelogs:

• https://github.com/krakend/krakend-ce/releases/tag/v2.12.0
• https://github.com/krakend/krakend-ce/compare/v2.11.2...v2.12.0

Approved by: yuri@ (Mentor)
Differential Revision: https://reviews.freebsd.org/D53461