getTimeOffset(...) returns with HTTP status code 411 error

[mxscho]

The POST request to https://api.steampowered.com/ITwoFactorService/QueryTime/v1/ returns with HTTP status code 411 (Length Required).
By adding...

"headers": {
    "Content-Length": 0
}

to the request's options it works.
I hope it's not my fault and this is indeed an error.
I will make a pull request, but it's up to you to accept it or not.