Remove Qt layout warning

src/Mara/Gui/RendererControl.cpp

@@ -8,11 +8,11 @@ namespace Mara {
 RendererControl::RendererControl( QWidget* /*parent*/ ) {
     setupUi( this );
 
-    auto textureSelectorLayout = new QHBoxLayout( this );
+    auto textureSelectorLayout = new QHBoxLayout();
     textureSelectorLayout->addWidget( new QLabel( "Image to display" ) );
     m_textureList = new QComboBox();
     textureSelectorLayout->addWidget( m_textureList );
-    panelLayout->addLayout(textureSelectorLayout);
+    panelLayout->addLayout( textureSelectorLayout );
     panelLayout->addStretch();
 
     connect( rendererList,