fix: always update global progress of sequential tasks

Previously, it would not update the global counter if the subTask didn't
update its progress, even though progress was being made.

This also prevents a segmentation fault while aborting the task.

Signed-off-by: flow <flowlnlnln@gmail.com>

launcher/tasks/SequentialTask.h

@@ -44,4 +44,6 @@ protected:
 
     qint64 m_stepProgress = 0;
     qint64 m_stepTotalProgress = 100;
+
+    bool m_aborted = false;
 };