fix warnings: enumeration values 'XX' not handled in switch [-Wswitch-enum]

src/qt/sendcoinsdialog.cpp

@@ -154,6 +154,8 @@ void SendCoinsDialog::on_sendButton_clicked()
             tr("Error: The transaction was rejected.  This might happen if some of the coins in your wallet were already spent, such as if you used a copy of wallet.dat and coins were spent in the copy but not marked as spent here."),
             QMessageBox::Ok, QMessageBox::Ok);
         break;
+    case WalletModel::Aborted: // User aborted, nothing to do
+        break;
     case WalletModel::OK:
         accept();
         break;