mtest: terminate test with SIGQUIT on timeout
mtest: terminate test with SIGQUIT on timeout

This gives us the chance to generate a core dump when a test timeout

pexip/meson,pexip/meson,pexip/meson,pexip/meson,pexip/meson,pexip/meson,pexip/meson,pexip/meson,pexip/meson,pexip/meson