Fixes a nil pointer when the Publish succeeds. In that case the err is nil, and calling .Error() on nil causes a nil pointer exception. Reproduced at: https://play.golang.com/p/ps8d82Qt9kO
Fixes a nil pointer when the Publish succeeds. In that case the err is nil, and calling .Error() on nil causes a nil pointer exception. Reproduced at: https://play.golang.com/p/ps8d82Qt9kO