QmlJSModelManager: Use Utils::runAsync instead of QtConcurrent::run

To get rid of the shared thread pool (and to use the API with the less
ugly implementation).

Change-Id: Ia93977b8b394aff8e410d6d81446c23e32b7aed5
Reviewed-by: Marco Benelli <marco.benelli@theqtcompany.com>
Reviewed-by: Eike Ziller <eike.ziller@theqtcompany.com>

src/libs/qmljs/qmljsmodelmanagerinterface.cpp

@@ -319,7 +319,7 @@ QFuture<void> ModelManagerInterface::refreshSourceFiles(const QStringList &sourc
     if (sourceFiles.isEmpty())
         return QFuture<void>();
 
-    QFuture<void> result = QtConcurrent::run(&ModelManagerInterface::parse,
+    QFuture<void> result = Utils::runAsync<void>(&ModelManagerInterface::parse,
                                                  workingCopyInternal(), sourceFiles,
                                                  this, Dialect(Dialect::Qml),
                                                  emitDocumentOnDiskChanged);