pull rebase --pause message is not clear enough

Reported by @mihails-strasuns-sociomantic in #42:

---

When I do hit hub rebase --pause and there are rebase conflicts, next first "continue" succeeds only partially:

```
$ git hub pull rebase --continue 
Rebase done, now pausing. Use --continue when done.
$ git hub pull rebase --continue 
Pushing results to master in git@github.com:user/repo.git
[12345678] This pull request has been rebased via `git hub pull rebase`… (mihails-strasuns-sociomantic)
```