Fix QT4 build

Author: Andrii Boichuk

inc/extension_qt/qml_view_executor.h

@@ -99,8 +99,8 @@ class QQmlViewCmdExecutor : public QViewCmdExecutor {
     virtual void SetPlayingPosition(const ElementId& element, double, Error** error) NOT_SUPPORTED_IMPL;
     virtual void SetMute(const ElementId& element, bool, Error**error) NOT_SUPPORTED_IMPL;
     virtual void GetMute(const ElementId& element, bool*, Error**error) NOT_SUPPORTED_IMPL;
-    virtual void SetPlaybackSpeed(const ElementId& element, double, Error**) NOT_SUPPORTED_IMPL;;
-    virtual void GetPlaybackSpeed(const ElementId& element, double*, Error**) NOT_SUPPORTED_IMPL;;
+    virtual void SetPlaybackSpeed(const ElementId& element, double, Error**error) NOT_SUPPORTED_IMPL;;
+    virtual void GetPlaybackSpeed(const ElementId& element, double*, Error**error) NOT_SUPPORTED_IMPL;;
     virtual void VisualizerSource(std::string* source, Error** error) NOT_SUPPORTED_IMPL;
     virtual void VisualizerShowPoint(Error** error) NOT_SUPPORTED_IMPL;