Add rejectUnauthorized as an option and fix error message when "response" is null

Add rejectUnauthorized as an option to use "http_upload" in no SSL mode

Fix Error response when "response" is null
```js
} else {
  if (response !== null) {
  ...
  }
}
```
would be better like this

```js
} else if (response !== null) {
  ...
}
```