Admin: Fix user record couldn't generate a title without account_id

This caused import of new users to fail.

admin/inc/class.admin_egw_user_record.inc.php

@@ -81,7 +81,8 @@ class admin_egw_user_record implements importexport_iface_egw_record
 	 *@return string title
 	 */
 	public function get_title() {
-		return Api\Accounts::username($this->identifier);
+		return $this->identifier ? Api\Accounts::username($this->identifier) :
+			Accounts::format_username($this->account_lid, $this->account_firstname, $this->account_lastname, $this->identifier);
 	}
 
 	/**