use placeholder 'release' when git id is missing
use placeholder 'release' when git id is missing

The reported version includeds the git short-id of the release. If you
are building from the release tar.gz or otherwise w/o the git repo the
spot for the git-id is just blank. This fills that in with 'release' so
it doesn't look as odd.

hashicorp/consul-template,hashicorp/consul-template