Handle Cases Where All Apps Are Already Downloaded

In the case where all of the apps are already present on the server, the install apps_profile_download_batch_finished() function will return $success == 1 but will not have a $results array which breaks the $_SESSION['update_manager_update_projects'] = $results['projects']; I went ahead and added a check to make sure $results exists before assigning the $_SESSION['update_manager_update_projects'] value.