Module "include_vars" fails with when using "file" parameter

Hi,

when using the include_module with the "file" parameter, it fails with

     AttributeError: 'NoneType' object has no attribute 'startswith'.

This works fine:

----- testmyvars_1.yml -----------

that parameter got added in 2.2, which you are using, but the error
seems to be from trying to use it in an older version.