qmljs: delay import scan until at least one qml file is parsed

Task-number: QTCREATORBUG-10899
Change-Id: I5dca739a89434c7b5813c7a79a76ab7c22e3d71d
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>

src/plugins/qmljstools/qmljsmodelmanager.h

@@ -179,6 +179,7 @@ private:
     QmlJS::QmlLanguageBundles m_activeBundles;
     QmlJS::QmlLanguageBundles m_extendedBundles;
     QmlJS::ViewerContext m_vContext;
+    bool m_shouldScanImports;
     QSet<QString> m_scannedPaths;
 
     QTimer *m_updateCppQmlTypesTimer;