Prometheus exporters and pushgateway: Strip golang binaries.

TLDR; turns out to be a misconception, has gone with dinosaurs.
Golang Project treat such cases as bugs, submit any evidence to them.
More info: https://honnef.co/posts/2016/10/go-and-strip/

Fix my port and ports I've committed yesterday.
Bump PORTREVISION.

Reported by: swills
Approved by: portmgr (just fix it)