Service portal view fails

If i set a Service under Configuration->Services and i do not set `Service Group` variable then the service portal view will fail.
This happens because the view has a condition

if(!empty($c['CoService']['co_group_id']))

that does not allow certain variables to be initiated. On the other hand the validation performed by COManage does not force the assignment of the co_group_id variable.

    'co_group_id' => array(

      'rule' => 'numeric',

      'required' => false,

      'allowEmpty' => true

    ),