Fix the following segmentation fault: ModemManager[128007]: mm_port_peek_kernel_device: assertion 'MM_IS_PORT (self)' failed Thread 1 "ModemManager" received signal SIGSEGV, Segmentation fault. 0x00005555556c6e3e in mm_kernel_device_get_global_property (self=0x0, property=0x7ffff5947480 "ID_MM_TELIT_BND_ALTERNATE") at kerneldevice/mm-kernel-device.c:309 Reported by Carlo Lobrano <c.lobrano@gmail.com>