cross out old issue about IP parsing in Readme

https://github.com/capistrano/sshkit/commit/f08da509a24eaf8cf2e70dee2fb80c528e184cb5#diff-27f6398b456a49b4df44c2816ab00153R20
Merge pull request #68 from sergey-alekseev/master

cross out old issue about IP parsing in Readme