Update ClipThumbs.qml for qml2 ScrollView

src/timeline2/view/qml/ClipThumbs.qml

@@ -39,7 +39,7 @@ Row {
             cache: enableCache
             property int currentFrame: thumbRepeater.count < 3 ? (index == 0 ? thumbRepeater.thumbStartFrame : thumbRepeater.thumbEndFrame) : Math.floor(clipRoot.inPoint + Math.round((index) * width / timeline.scaleFactor)* clipRoot.speed)
             horizontalAlignment: thumbRepeater.count < 3 ? (index == 0 ? Image.AlignLeft : Image.AlignRight) : Image.AlignLeft
-            source: thumbRepeater.count < 3 ? (clipRoot.baseThumbPath + currentFrame) : (index * width < clipRoot.scrollStart - width || index * width > clipRoot.scrollStart + scrollView.viewport.width) ? '' : clipRoot.baseThumbPath + currentFrame
+            source: thumbRepeater.count < 3 ? (clipRoot.baseThumbPath + currentFrame) : (index * width < clipRoot.scrollStart - width || index * width > clipRoot.scrollStart + scrollView.contentItem.width) ? '' : clipRoot.baseThumbPath + currentFrame
             onStatusChanged: {
                 if (thumbRepeater.count < 3) {
                     if (status === Image.Ready) {