Suricata

If Suricata is run in a pcap directory reading mode and the directory is empty, then Suricata crashes because FM doesn't get started in time.
Reproduced by:
suricata -r /tmp/pcap/ --pcap-file-continuous -vvvv

Likely because the code in flow-manager.c gets stuck and does not proceed with FM initialization:
```
/* don't start our activities until time is setup */
while (!TimeModeIsReady()) {
if (suricata_ctl_flags != 0)
return TM_ECODE_OK;
usleep(10);
}
```

Reported in https://forum.suricata.io/t/suricata-exits-with-errors-when-running-with-r-and-pcap-file-continuous/4396/2