For some reason these tests fail all the time on GitLab. I can
re-create the hang around 3% of the time locally but it doesn't seem
to be MTTCG related. For now skipIf on GITLAB_CI.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Cc: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
Message-Id: <20200701135652.1366-29-alex.bennee@linaro.org>