Fix ssh-keyscan with non default port

[kuuak]

ssh-keyscan was failling because our remote hosting server is not using default port number.

This PR fixes it by seting the port number with -p option on ssh-keyscan

[tykeal]

Would love to see this get merged

[marverix]

Hi, as it seems that this repo is not maintained anymore, I created a fork:
https://github.com/cdqag/action-configure-ssh-host

It's cleaned up, and removed sudo from chmod command, as a file owner does not need super user privilages to change rights on it own files.