Preventing errors if there is no $_SERVER['SCRIPT_NAME']

On some environments, when running through CLI, I've encountered cases where there is no 'SCRIPT_NAME' global set.
Good catch.

Could you format this with {} though. I'm trying to maintain PSR-2 compatibility with the codebase.

Something like:

```php
$this->url = 'N/A';
if (isset($this->serverData['REDIRECT_URL'])) {
   $this->url = $this->serverData['REDIRECT_URL'];
} elseif (isset($this->serverData['SCRIPT_NAME'])) {
   $this->url = $this->serverData['SCRIPT_NAME'];
}
```

Thanks!