repair sample layer view (#808)

This resolves #808 (closed).

GUI/View/SampleDesigner/SampleEditor.cpp

@@ -65,7 +65,7 @@ void SampleEditor::setCurrentSample(SampleItem* sampleItem)
 
     createLayerColors();
 
-    m_currentSampleWidget = new SampleForm(this, m_currentSample, ec);
+    m_currentSampleWidget = new SampleForm(m_currentSample, ec);
     ec->setSampleForm(m_currentSampleWidget);
     m_currentSampleWidget->setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Minimum);
     QScrollArea::setWidget(m_currentSampleWidget);