debian: running -version doesn't contain the sha1

[agis]

When we build with make build, the sha1 of the tip is appended to the version displayed when doing rafka -version. However, the debian package doesn't contain this info. I assume this is because dh-make-golang does a go build instead of make build.

If my above assumptions are true, it'd be good if we could customize the procedure to use make build instead.