Fix build errors

Author: nyalldawson

python/core/composer/qgscomposerhtml.sip

@@ -155,6 +155,6 @@ class QgsComposerHtml: QgsComposerMultiFrame
 
     void refreshExpressionContext();
 
-    virtual void refreshDataDefinedProperty( QgsComposerObject::DataDefinedProperty property = QgsComposerObject::AllProperties );
+    virtual void refreshDataDefinedProperty( const QgsComposerObject::DataDefinedProperty property = QgsComposerObject::AllProperties );
 
 };

src/core/composer/qgscomposerhtml.cpp

@@ -484,7 +484,7 @@ void QgsComposerHtml::refreshExpressionContext()
   loadHtml();
 }
 
-void QgsComposerHtml::refreshDataDefinedProperty( QgsComposerObject::DataDefinedProperty property )
+void QgsComposerHtml::refreshDataDefinedProperty( const QgsComposerObject::DataDefinedProperty property )
 {
   //updates data defined properties and redraws item to match
   if ( property == QgsComposerObject::SourceUrl || property == QgsComposerObject::AllProperties )

src/core/composer/qgscomposerhtml.h

@@ -178,7 +178,7 @@ class CORE_EXPORT QgsComposerHtml: public QgsComposerMultiFrame
 
     void refreshExpressionContext();
 
-    virtual void refreshDataDefinedProperty( QgsComposerObject::DataDefinedProperty property = QgsComposerObject::AllProperties );
+    virtual void refreshDataDefinedProperty( const QgsComposerObject::DataDefinedProperty property = QgsComposerObject::AllProperties );
 
   private slots:
     void frameLoaded( bool ok = true );