message: qt: prevent negative values of progressPerHour
  Added a similar guard to progressPerHour as is placed at remainingMSecs.
  It prevents the display of negative values like "-0.00%" in some cases.
diff: @@ -108,7 +108,7 @@ void ModalOverlay::tipUpdate(int count, const QDateTime& blockDate, double nVeri
  if (sample.first < (currentDate.toMSecsSinceEpoch() - 500 * 1000) || i == blockProcessTime.size() - 1) {
  progressDelta = blockProcessTime[0].second - sample.second;
  timeDelta = blockProcessTime[0].first - sample.first;
  - progressPerHour = progressDelta / (double) timeDelta * 1000 * 3600;
  + progressPerHour = (progressDelta > 0) ? progressDelta / (double)timeDelta * 1000 * 3600 : 0;
  remainingMSecs = (progressDelta > 0) ? remainingProgress / progressDelta * timeDelta : -1;
  break;
  }
  