Check for empty account object in submit handler.

I am getting Error: Call to a member function id() on null in _user_registrationpassword_user_pass_submit() (line 480 of /user_registrationpassword/user_registrationpassword.module) after applying patch https://www.drupal.org/files/issues/2018-11-14/password-reset-text-15219... to resolve issue https://www.drupal.org/project/drupal/issues/1521996. This is happening because the $account object is null in the submit handler.

Proposed resolution:
Adding check for an empty object in submit handler.