The script assumes that the name of the remote is `origin`, but this
is not the case if the user has set `clone.defaultRemoteName` to
another value in the ~/.gitconfig (or elsewhere in the configuration).
Adding `-o origin` ensures that the remote will be called `origin`
regardless of the `clone.defaultRemoteName` setting.
Per PR #3341:
- The minimum Git version this should work with is v1.7.10. (This is not
documented in the repo itself; it's just an implicit requirement.)
- The `--origin` option was added to `git clone` in commit 98a4fef3f2 which
was released in v1.2.5. From the diff of that commit, the `-o` option was
already available at that time. So this easily satisfies the above.
- A comment in #3341 indicates that `-o` was added in v1.1.0. I've not
verified this, but we probably don't need to track that down since by the
above we're already well within requirements.
