So that different concurrent runs of this same test don't clash with
each other:
TEST: test-service-generic... (pid=11124)
/MM/Service/Generic/enable-disable: Activating service name='org.freedesktop.ModemManager1'
Successfully activated service 'org.freedesktop.ModemManager1'
** (plugins/.libs/lt-test-service-generic>:11124): ERROR **: Cannot bind socket: Error binding to address: Address already in use
cleaning up pid 11144
FAIL