Fix bad first argument of `SSHCopyID`.

* Keep a reference to the passed `opts` since they are used further down the class.
Work around pylint bug of wrongly reporting too many arguments.

More info on http://hustoknow.blogspot.pt/2013/06/pylint.html
Merge pull request #6140 from s0undt3ch/hotfix/pylint-bad-first-argument

Hotfix pylint bad first argument