net-mgmt/netdata-go: Update to 0.31.2

Changes: https://github.com/netdata/go.d.plugin/releases/tag/v0.31.1
Changes: https://github.com/netdata/go.d.plugin/releases/tag/v0.31.2
Approved by: 0mp (mentor)
MFH: 2022Q1
Differential Revision: https://reviews.freebsd.org/D33929

(cherry picked from commit c8f506bfb4eca56f87bae119e8507be243def6ad)