Use Qt5 connect syntax

src/gui/previewselectdialog.cpp

@@ -96,7 +96,6 @@ PreviewSelectDialog::PreviewSelectDialog(QWidget *parent, BitTorrent::TorrentHan
         }
     }
 
-    connect(this, SIGNAL(readyToPreviewFile(QString)), parent, SLOT(previewFile(QString)));
     m_previewListModel->sort(NAME);
     m_ui->previewList->header()->setSortIndicator(0, Qt::AscendingOrder);
     m_ui->previewList->selectionModel()->select(m_previewListModel->index(0, NAME), QItemSelectionModel::Select | QItemSelectionModel::Rows);

src/gui/transferlistwidget.cpp

@@ -605,12 +605,15 @@ void TransferListWidget::openSelectedTorrentsFolder() const
 void TransferListWidget::previewSelectedTorrents()
 {
     for (BitTorrent::TorrentHandle *const torrent : asConst(getSelectedTorrents())) {
-        if (torrentContainsPreviewableFiles(torrent))
-            new PreviewSelectDialog(this, torrent);
-        else
+        if (torrentContainsPreviewableFiles(torrent)) {
+            const auto *dialog = new PreviewSelectDialog(this, torrent);
+            connect(dialog, &PreviewSelectDialog::readyToPreviewFile, this, &TransferListWidget::previewFile);
+        }
+        else {
             QMessageBox::critical(this, tr("Unable to preview"), tr("The selected torrent does not contain previewable files"));
         }
     }
+}
 
 void TransferListWidget::setDlLimitSelectedTorrents()
 {