Typo in return value key "stdtout"

[jackm]

There is a typo in file virtualbox.yml:38 which references the return value key stdtout (with an extra 't') instead of stdout.

You will see the following when running a play using this task:

TASK [stefanhorning.virtualbox : Output installed extpacks] ***************************************************************************************************************************************************************************
ok: [localhost] => {
    "download_result.stdtout": "VARIABLE IS NOT DEFINED!"
}