Authentication for users with empty db password

Problem

If the user does not have password set in the database, and if the user trys to authenticate in translate5 error is produced with the following stack trace:

ERROR TypeError: E9999 - ZfExtended_Authentication::isPasswordEqual(): Argument #2 ($passwordHash) must be of type string, null given, called in /var/www/translate5/library/ZfExtended/Authentication.php on line 215
  in core in file:///var/www/translate5/library/ZfExtended/Authentication.php:230  
  Request: POST http://translate5.local/login
  Trace: 
    #0 in file:///var/www/translate5/library/ZfExtended/Authentication.php:215  ZfExtended_Authentication->isPasswordEqual()
    #1 in file:///var/www/translate5/library/ZfExtended/Authentication.php:276  ZfExtended_Authentication->{closure}()
    #2 in file:///var/www/translate5/library/ZfExtended/Authentication.php:216  ZfExtended_Authentication->loadUserAndValidate()
    #3 in file:///var/www/translate5/library/ZfExtended/Controllers/Login.php:148  ZfExtended_Authentication->authenticate()
    #4 in file:///var/www/translate5/library/ZfExtended/Controllers/Login.php:84  ZfExtended_Controllers_Login->isValidLogin()
    #5 in file:///var/www/translate5/application/modules/default/Controllers/LoginController.php:69  ZfExtended_Controllers_Login->indexAction()
    #6 in file:///var/www/translate5/vendor/shardj/zf1-future/library/Zend/Controller/Action.php:516  LoginController->indexAction()
    #7 in file:///var/www/translate5/vendor/shardj/zf1-future/library/Zend/Controller/Dispatcher/Standard.php:308  Zend_Controller_Action->dispatch()
    #8 in file:///var/www/translate5/vendor/shardj/zf1-future/library/Zend/Controller/Front.php:954  Zend_Controller_Dispatcher_Standard->dispatch()
    #9 in file:///var/www/translate5/vendor/shardj/zf1-future/library/Zend/Application/Bootstrap/Bootstrap.php:105  Zend_Controller_Front->dispatch()
    #10 in file:///var/www/translate5/vendor/shardj/zf1-future/library/Zend/Application.php:399  Zend_Application_Bootstrap_Bootstrap->run()
    #11 in file:///var/www/translate5/library/ZfExtended/Application.php:74  Zend_Application->run()
    #12 in file:///var/www/translate5/library/ZfExtended/BaseIndex.php:174  ZfExtended_Application->run()
    #13 in file:///var/www/translate5/public/index.php:35  ZfExtended_BaseIndex->startApplication()
    #14 {main}