UI: Fix about window placement

src/UI/AboutWindow.cc

@@ -89,7 +89,7 @@ public:
 
 // Construct the AboutWindow
 AboutWindow::AboutWindow(QWidget *parent) noexcept
-    : QMainWindow(parent)
+    : QMainWindow(parent, Qt::Dialog)
     , panels(new QTabWidget)
 {
     setWindowIcon(QIcon(VIVY_ICON_APP));