StandardNodeGadget : Fix dimming of BoxIO labels

These are TextGadgets displaying the name of the external plug, so were being ignored by the cast to NameGadget.

Changes.md

@@ -25,6 +25,7 @@ Fixes
 - Scene Editors : Fixed update when ScenePlugs are added to or removed from the node being viewed.
 - PrimitiveInspector : Fixed failure to update when the location being viewed ceases to exist, or is recreated.
 - Shuffle, ShuffleAttributes, ShufflePrimitiveVariables : Fixed some special cases where shuffling a source to itself would fail to have the expected effect.
+- GraphEditor : Fixed dimming of labels for BoxIn and BoxOut nodes.
 
 API
 ---

src/GafferUI/StandardNodeGadget.cpp

@@ -797,10 +797,9 @@ void StandardNodeGadget::updateFromContextTracker( const ContextTracker *context
 
 void StandardNodeGadget::updateTextDimming()
 {
-	NameGadget *name = IECore::runTimeCast<NameGadget>( getContents() );
-	if( name )
+	if( auto text = IECore::runTimeCast<TextGadget>( getContents() ) )
 	{
-		name->setDimmed( !( m_active || getHighlighted() ) );
+		text->setDimmed( !( m_active || getHighlighted() ) );
 	}
 }