Insufficient scope error while scope is correct

### Description
I'm consistently getting an "Insufficient scope" error when trying to export the order data using the CLI export tool. The command I'm using is:

```order-export --projectKey --accessToken --targetDir c:/tmp --logDir c:/tmp --csvTemplate c:/tmp/header.txt ```

This is working fine for the customer-export using the same project-key and access token. The scope is configured correctly in Commercetools: the credentials have read-only access to all entities (including customer and order).

### Expected Behavior
Create a local order export for the specified project key.

### Current Behavior
Receiving an Insufficient scope error. This is the case when providing only an access key, only client-id and client-secret, and when providing all three. The same behavior occurs when using credentials that have manage-orders access. Also specifying the sphereHost and/or sphereAuthHost do not help. Exporting the orders using the Impex tool also works fine.

### Stacktrace
```
{
"name": "sphere-order-export-2.2.3",
"hostname": "",
"pid": 17576,
"level": 50,
"data": {
"body": {
"statusCode": 403,
"message": "Insufficient scope",
"errors": [{
"code": "insufficient_scope",
"message": "Insufficient scope"
}],
"error": "insufficient_scope",
"error_description": "Insufficient scope",
"originalRequest": {
"endpoint": "/channels",
"payload": {
"key": "OrderXmlFileExport",
"roles": ["OrderExport"]
},
"options": {
"config": {
"project_key": ""
},
"host": "api.sphere.io",
"protocol": "https",
"timeout": 60000,
"rejectUnauthorized": true,
"headers": {
"User-Agent": "sphere-order-export - 2.2.3",
"Authorization": "Bearer "
},
"uri": "https://api.sphere.io/",
"gzipEnable": true
}
}
},
"message": "Forbidden",
"name": "HttpError",
"stack": "HttpError: Forbidden\n at \\Roaming\\npm\\node_modules\\sphere-order-export\\node_modules\\sphere-node-sdk\\lib\\services\\base.js:518:22\n at ChannelService.BaseService._wrapResponse (\\Roaming\\npm\\node_modules\\sphere-order-export\\node_modules\\sphere-node-sdk\\lib\\services\\base.js:523:11)\n at \\Roaming\\npm\\node_modules\\sphere-order-export\\node_modules\\sphere-node-sdk\\lib\\services\\base.js:400:40\n at Request._callback (\\Roaming\\npm\\node_modules\\sphere-order-export\\node_modules\\sphere-node-sdk\\lib\\connect\\rest.js:166:14)\n at Request.self.callback (\\Roaming\\npm\\node_modules\\sphere-order-export\\node_modules\\request\\request.js:185:22)\n at Request.emit (events.js:203:13)\n at Request. (\\Roaming\\npm\\node_modules\\sphere-order-export\\node_modules\\request\\request.js:1161:10)\n at Request.emit (events.js:203:13)\n at Gunzip. (\\Roaming\\npm\\node_modules\\sphere-order-export\\node_modules\\request\\request.js:1083:12)\n at Object.onceWrapper (events.js:291:20)\n at Gunzip.emit (events.js:208:15)\n at endReadableNT (_stream_readable.js:1168:12)\n at processTicksAndRejections (internal/process/task_queues.js:77:11)",
"code": 403,
"statusCode": 403
},
"project_key": "",
"msg": "Oops, something went wrong!",
"time": "2019-09-23T09:01:36.048Z",
"v": 0
}
```

Using sphere-order-export version 2.2.3.