too bad we don't have a "finally" on promises :(

```javascript
// non working code
return new Promise(function(resolve, reject) {
  request.onsuccess = function onSuccess(evt) {
    resolve(evt.target.result);
  };
  request.onerror = function onError(evt) {
    reject(evt.target.error);
  };
}).finally(function() {
  MessageManager.deleteMessage(message.id)
});
```