"Show QR code" only for "new" addresses

scripts/joinmarket-qt.py

@@ -1171,6 +1171,8 @@ class JMWalletTab(QWidget):
         if address_valid:
             menu.addAction("Copy address to clipboard",
                            lambda: app.clipboard().setText(txt))
+            # Show QR code option only for new addresses to avoid address reuse
+            if item.text(3) == "new":
                 menu.addAction("Show QR code",
                                lambda: self.openQRCodePopup(txt))
         if xpub_exists: