Fix a typo in publish.go

[wzhd]

This typo can be seen by running ipfs name publish --help

[GitCop]

There were the following issues with your Pull Request

• Commit: 5a0354a
  • Invalid signoff. Commit message must end with
    License: MIT
    Signed-off-by: .* <.*>

We ask for a few features in the commit message for Open Source licensing hygiene and commit message clarity.
git commit --amend can often help you quickly improve the commit message.
Guidelines and a script are available to help in the long run.
Your feedback on GitCop is welcome on this issue.

---

This message was auto-generated by https://gitcop.com

[wzhd]

Okay, I used git commit --amend to update the commit message

[whyrusleeping]

Good catch, thanks!