QmlDesigner: Remove call to clearComponentCache()

This is called also the first time and can have unwanted side effects.

Change-Id: I373dd748499c9f924a3263796e4cd584959f55ac
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/plugins/insight/insightwidget.cpp

@@ -103,7 +103,6 @@ void InsightWidget::reloadQmlSource()
 {
     QString statesListQmlFilePath = qmlSourcesPath() + QStringLiteral("/Main.qml");
     QTC_ASSERT(QFileInfo::exists(statesListQmlFilePath), return );
-    engine()->clearComponentCache();
     setSource(QUrl::fromLocalFile(statesListQmlFilePath));
 
     if (!rootObject()) {