Fix unstable test_server_compiler_pool_template_proc_exit
Fix unstable test_server_compiler_pool_template_proc_exit

It's likely that the test killed the template process too early before
the latter has a chance to setup the signal handlers. In real life, we
should depend on the supervisor daemon to restart the server.

edgedb/edgedb,edgedb/edgedb,edgedb/edgedb