Fix Users data to respect 'is_group' fields that is required for auth pr...

Fix Users data to respect 'is_group' fields that is required for auth process in current version

Users in current auth version are fetched by this code:

        $userBean = $userBean->retrieve_by_string_fields(
            array(
                'user_name'=>$username,
                'deleted'=>'0',
                'status'=>'Active',
                'portal_only'=>'0',
                'is_group'=>'0',
            ));

So 'is_group' field should have 0 value for successful login.