Clear message before showing a new one.

mainwindow.cpp

@@ -224,6 +224,7 @@ void MainWindow::onReplaceLast(QString text, QString suffix) {
 }
 
 void MainWindow::onShowErrorMessage(QString title, QString text) {
-    this->statusBar()->showMessage( // timeout: 5000
-        QString(title + ": " + text).leftJustified(80, ' '), 20000);
+    this->statusBar()->clearMessage();
+    this->statusBar()->showMessage( // timeout: 10000
+        QString(title + ": " + text).leftJustified(80, ' '), 10000);
 }