QmlJS: Set default import paths in constructor.

Also, remove the import path of the Qt that Creator was built with. It
might make things seem to work on built-from-source Creators that will
fail when Creator is shipped.

Reviewed-by: Erik Verbruggen

src/plugins/qmljstools/qmljsmodelmanager.cpp

@@ -74,7 +74,7 @@ ModelManager::ModelManager(QObject *parent):
     loadQmlTypeDescriptions();
 
     m_defaultImportPaths << environmentImportPaths();
-    m_defaultImportPaths << QLibraryInfo::location(QLibraryInfo::ImportsPath);
+    updateImportPaths();
 }
 
 void ModelManager::loadQmlTypeDescriptions()