QbsProjectManager: Directly delete project parser

It holds a pointer to the future which is deleted directly 3 lines
below. And a signal (taskStarted) can come to the parser before it gets
deleted, then accessing the deleted future. Which results in a
segmentation fault.

Change-Id: I468c6477023488d6d922d6bf621cba886740d8f4
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/qbsprojectmanager/qbsproject.cpp

@@ -561,7 +561,7 @@ void QbsBuildSystem::handleQbsParsingDone(bool success)
         m_qbsUpdateFutureInterface->reportCanceled();
     }
 
-    m_qbsProjectParser->deleteLater();
+    delete m_qbsProjectParser;
     m_qbsProjectParser = nullptr;
     m_qbsUpdateFutureInterface->reportFinished();
     delete m_qbsUpdateFutureInterface;