Fix error in command

[stsewd]

This fix an error introduced in https://github.com/rtfd/readthedocs.org/pull/4321/files#r200705086

From django:

Now that management commands use argparse for argument parsing, all arguments are passed in **options by default, unless you name your positional arguments to args (compatibility mode). You are encouraged to exclusively use **options for new commands.

This is the only command that I found using args, so the others should be fine.

[ericholscher]

Looks good. Sorry I didn't catch this on initial review!

[humitos]

Here we need to check if options now instead of if args otherwise it fails in a weird way :)