Misc/update newsfrag for the app stop logic refactor (#1143)

doc/newsfragments/3041_changed.app_stop.rst

@@ -1 +1,2 @@
-Refactor the stop logic of :py:class:`App <~testplan.testing.multitest.driver.app.App>` driver for faster environment shutdown. Rename parameter ``sigint_timeout`` to ``stop_timeout``. Add a new parameter ``stop_signal`` for custom stop signals, its default value ``None`` invokes ``terminate`` method on subprocess during stop.
+Refactor the stop logic of :py:class:`App <~testplan.testing.multitest.driver.app.App>` driver for faster environment shutdown. Rename parameter ``sigint_timeout`` to ``stop_timeout``. Add a new parameter ``stop_signal`` for custom stop signals, its default value ``None`` invokes ``terminate`` method to stop subprocess, i.e. sending ``SIGTERM`` signal to subprocess on Linux.
+**Environment will fail to stop if subprocess doesn't terminate within the default 5-second** ``stop_timeout`` **for graceful shutdown**. Increase ``stop_timeout`` or change ``stop_signal`` (to maybe ``SIGKILL`` on Linux) could resolve this issue.