error_code not passed to reply when catching exception in executeCall()

[jensschuppe]

At least for the local connector (cURL not checked), when doing

$call->setStatus(Call::STATUS_FAILED, $e->getMessage());

CiviCRM's error_message is not passed through and is thus not available within the call's reply property.
At least for the local connector, only CiviCRM_API3_Exceptions should be caught, and their error code be passed using

$call->setStatus(Call::STATUS_FAILED, $e->getMessage(), $e->getErrorCode());