Bug#827219: [pkg-go] Bug#827219: dh-golang: Built-Using calculation crashes on "golang-google-cloud"

[Michael Hudson-Doyle]

While this bug report makes sense, I can't reproduce the problem. Does
it only fail on some version of golang-google-cloud in git that you
haven't pushed to alioth or something? I'll try to code up a fix but
it would be nice to test that it actually helps.