fixes microsoft server _sometimes_ failing due to un-required token

[jzacsh]

we're sometimes seeing the following microsoft server response at the uploadChunk() callsite:

MicrosoftApiResponse{httpStatus=401, httpMessage=, body=Optional[
{
    "error": {
        "code": "unauthenticated",
        "message": "Unauthenticated"
    }
}
]}

which according to their documentation is because we simply aren't supposed to send the token during our chunked byte-upload sequence (PUT), but only during our createSession (POST) call at the start:

If you include the Authorization header when issuing the PUT call,
it may result in an HTTP 401 Unauthorized response. Only send the
Authorization header and bearer token when issuing the POST during
the first step. Don't include it when you issue the PUT call.

-- https://learn.microsoft.com/en-us/graph/api/driveitem-createuploadsession?view=graph-rest-1.0#remarks