ProjectExplorer: Add missing member in Task::clear()

Change-Id: Iab8ca5fa67406eb05f256fbfcd7e1ded4fdf1a73
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/projectexplorer/task.cpp

@@ -85,6 +85,7 @@ void Task::clear()
     file = Utils::FilePath();
     line = -1;
     movedLine = -1;
+    column = 0;
     category = Utils::Id();
     m_icon = QIcon();
     formats.clear();