git-codereview: ensure blank line after subject

Fixes golang/go#9522

Change-Id: Ic06feda22711fe320a789957620af98f38f1df8f
Reviewed-on: https://go-review.googlesource.com/4130
Reviewed-by: Andrew Gerrand <adg@golang.org>
2 files changed
tree: 15bc46cc900172bfde8c4bf366b520cfd1d3c64a
  1. .gitattributes
  2. README
  3. git-codereview/