Cluster sometimes fails to configure on package installation

On a few occasions, I've installed the deb packages on my Ubuntu 16.04 box and found that the cluster did not successfully get configured (i.e. it couldn't run `configure new single memory`). Looking in the logs, it seems that the `fdbserver` processes failed to start because they couldn't read the cluster file:

```
Unable to read cluster file `/etc/foundationdb/fdb.cluster': 1515 No cluster file found in current directory or default location
```

They restarted immediately and had the same problem, then they waited 60 seconds and were able to read the file. After that, I could open `fdbcli` and perform the configuration myself.