qt: Avoid potential -Wdeprecated-enum-enum-conversion warning

src/qt/transactionview.cpp

@@ -550,7 +550,7 @@ void TransactionView::openThirdPartyTxUrl(QString url)
 QWidget *TransactionView::createDateRangeWidget()
 {
     dateRangeWidget = new QFrame();
-    dateRangeWidget->setFrameStyle(QFrame::Panel | QFrame::Raised);
+    dateRangeWidget->setFrameStyle(static_cast<int>(QFrame::Panel) | static_cast<int>(QFrame::Raised));
     dateRangeWidget->setContentsMargins(1,1,1,1);
     QHBoxLayout *layout = new QHBoxLayout(dateRangeWidget);
     layout->setContentsMargins(0,0,0,0);