Fix: don't select light paths with Alt or Shift

This affects the area region selection tool.

Author: oktomus

src/appleseed.studio/mainwindow/rendering/viewportregionselectionhandler.cpp

@@ -112,7 +112,8 @@ bool ViewportRegionSelectionHandler::eventFilter(QObject* object, QEvent* event)
             {
                 const QMouseEvent* mouse_event = static_cast<QMouseEvent*>(event);
 
-                if (mouse_event->button() == Qt::LeftButton)
+                if (mouse_event->button() == Qt::LeftButton &&
+                    !(mouse_event->modifiers() & (Qt::AltModifier | Qt::ShiftModifier | Qt::ControlModifier)))
                 {
                     m_rubber_band->hide();