`__modules__` isn't a global, although `__salt__` is
`__modules__` isn't a global, although `__salt__` is

This method is attempting to access the loader so that it can get an error message. The module loader is `__salt__` not `__modules__`. This before was throwing an exception in __virtual__ if dockerng.version wasn't in the modules. Pylint was also complaining about this, so I've remove the pylint override that was placed here as well.

saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt