fix warning about returning temporary objects

git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@9076 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: jef

python/core/qgslabelattributes.sip

@@ -83,7 +83,7 @@ public:
 
     void  setBufferColor ( const QColor &color );
     bool  bufferColorIsSet ( ) const;
-    const QColor & bufferColor ( ) const;
+    QColor bufferColor ( ) const;
 
     void  setBufferStyle ( Qt::BrushStyle style );
     bool  bufferStyleIsSet ( ) const;