message: Remove QString::null deprecation warnings
diff: @@ -140,7 +140,7 @@ protected:
  // Check if User set a file via File Picker
  QString chosenFile = m_webPage->filePicker(oldFile);
  - if (chosenFile == QString::null && m_uploadFiles.count() > 0) {
  + if (chosenFile.isNull() && m_uploadFiles.count() > 0) {
  // Check if instead User set a file via uploadFile API
  chosenFile = m_uploadFiles.first();
  }
  @@ -785,7 +785,7 @@ QString WebPage::filePicker(const QString& oldFile)
  }
  }
  }
  - return QString::null;
  + return QString();
  }
  bool WebPage::javaScriptConfirm(const QString& msg)
  