Fix missing parameter error

The `JRCapture refreshAccessTokenForDelegate:context:` method was getting the following error response from the /oauth/refresh_access_token endpoint:

```
{
    "code": 100,
    "error": "missing_argument",
    "error_description": "missing arguments: flow, version",
    "request_id": "vf6ar4e7gjdwsprm",
    "stat": "error"
}
```
Adding the "flow" and "flow_version" parameters to the request fixed the issue.