Fixing error when No file was uploaded (or presumably other UploadError)

Without this fix I get the following error when trying to upload without selecting a file

```Warning (2): Invalid argument supplied for foreach()   [CORE/Cake/View/Helper/FormHelper.php, line 682]```

```
}
$tmp = array();
foreach ($error as &$e) {
```

```$error = 'No file was uploaded.'```
```
FormHelper::error() - CORE/Cake/View/Helper/FormHelper.php, line 682
FormHelper::input() - CORE/Cake/View/Helper/FormHelper.php, line 1005
include - APP/View/Profiles/picture.ctp, line 24
View::_evaluate() - CORE/Cake/View/View.php, line 947
View::_render() - CORE/Cake/View/View.php, line 909
View::render() - CORE/Cake/View/View.php, line 471
Controller::render() - CORE/Cake/Controller/Controller.php, line 948
Dispatcher::_invoke() - CORE/Cake/Routing/Dispatcher.php, line 194
Dispatcher::dispatch() - CORE/Cake/Routing/Dispatcher.php, line 162
[main] - APP/webroot/index.php, line 109
```