Fix multidimensional request parameters

This PR fixes multidimensional request parameters. For example, these parameters give : 

```
| password[first]  | test |
| password[second] | test |
```

**Before**
``array('password[first]' => 'test', 'password[second]' => 'test')``

**After**
``array('password' => array('first' => 'test, 'second' => 'test))``