jailer: fix bug causing unexpected exit
jailer: fix bug causing unexpected exit

When run only with the required parameters, the
jailer would crash. This is a regression introduced
by an earlier commit which changed the default location
of the firecracker socket.

Signed-off-by: Diana Popa <4240422768c1b315e51818a074064501037757cd@amazon.com>

firecracker-microvm/firecracker,firecracker-microvm/firecracker,firecracker-microvm/firecracker,firecracker-microvm/firecracker,firecracker-microvm/firecracker