title: Observable do not call onComplete (sqlbrite - mapToOneOrDefault)
body: <p>I have select from sqlbrite db but observable do not call onComplete for some reason. </p>
  
  <p>My code: </p>
  
  <pre><code>fun BriteDatabase.selectDayTimelineRecord(dayTimestamp: Long) =
  createQuery(table_timeline, selectWDayRecords(dayTimestamp)).subscribeOn(Schedulers.io()).observeOn(AndroidSchedulers.mainThread())
          .mapToOneOrDefault(StatItem(dayTimestamp, 0)) { cursor -&gt; cursor.mapTimelineStat() }
  </code></pre>
  
  <p>and then I try variants:</p>
  
  <ol>
  <li><p>working but I need to keep order so I can not use flatmap</p>
  
  <p>Observable.fromIterable(0..6).flatMap{
      db.selectDayTimelineRecords(timestampOfDayInWeek(it))
  }.buffer(7).subscribeOn(Schedulers.io()).observeOn(AndroidSchedulers.mainThread()).subscribe {}</p></li>
  <li><p>not working (not delivery result but I do not know why)</p>
  
  <p>Observable.fromIterable(0..6).concatMap{
      db.selectDayTimelineRecords(timestampOfDayInWeek(it))
  }.buffer(7).subscribeOn(Schedulers.io()).observeOn(AndroidSchedulers.mainThread()).subscribe {}</p></li>
  </ol>
  
  <p>As result I want Observable with list of T...</p>
  
  <p>Anyone know what am I doing wrong?</p>