Symphony 2.3 error with: Illegal string offset 'handle'

The call on [this line](https://github.com/kanduvisla/importcsv/blob/master/content/content.index.php#L75) creates an error in Symphony 2.3 ( *no error* in 2.3.1) because, the method ```ExtensionManager->fetchStatus($about)``` **requires** $about to be an array, it doesn't work with strings.

Note that Symphony 2.3.1 changed the behavior of this function to be able to work both styles: with a string or with an array.

This pull request ensures it works consistently in 2.2, 2.3 and 2.3.1.

How to reproduce problem:
 - Test on Symphony 2.3 (not 2.3.1)
 - Install the [Multilingual Text Box extension](https://github.com/6ui11em/multilingual_field) and all its dependencies
 - Enable Import / Export CSV
 - Go to the "Import/Export CSV" page
 - You should get a Symphony error "Illegal string offset 'handle'