AutoTest: Do not unnecessarily update QmlJS code model

We forgot to update the timestamp indicators which lead to several
triggered updates e.g. when modifying and storing a qml file inside
a watched directory.

Change-Id: I30858ea9e8073d648a84c7f188dff18ddef5b1c1
Reviewed-by: Eike Ziller <eike.ziller@qt.io>
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/autotest/quick/quicktestparser.cpp

@@ -312,6 +312,7 @@ void QuickTestParser::handleDirectoryChanged(const QString &directory)
             return filesAndDates.value(file) != watched.value(file);
         });
         if (timestampChanged) {
+            m_watchedFiles[directory] = filesAndDates;
             PathsAndLanguages paths;
             paths.maybeInsert(Utils::FilePath::fromString(directory), Dialect::Qml);
             QFutureInterface<void> future;