Repair regressions from repairing "ugly"

https://github.com/saltstack/salt/commit/879a0a083b10963eb58da6b5ea17fcf4c7626fa4

- dict.update returns None
- dict.get with default is logocally differnt from the original boolean test
Merge pull request #7551 from ajithhub/ssh_pep8_regression

Repair SSH regressions from repairing "ugly"