insufficient memory on armhf platform

I'm successfully using f3probe on my laptop. Thank you for this great tool.

I recently set up a Banana Pi SBC computer (armv7 armhf) and thought it would be cool to test this tool out on that platform. Agreed, the SBC is fairly limited but I thought 1GB of RAM and an additional 512GB of flash ought to be enough to run this tool. It isn't

```
pi@banana:~$ sudo f3probe /dev/sdb
F3 probe 8.0
Copyright (C) 2010 Digirati Internet LTDA.
This is free software; see the source for copying conditions.

Out of memory, try `f3probe --min-memory /dev/sdb'
pi@banana:~$ sudo f3probe --min-memory /dev/sdb
F3 probe 8.0
Copyright (C) 2010 Digirati Internet LTDA.
This is free software; see the source for copying conditions.

Out of memory, try `f3probe --destructive /dev/sdb'
Please back your data up before using option --destructive.
Alternatively, you could use a machine with more memory to run f3probe.
pi@banana:~$ free
total used free shared buff/cache available
Mem: 1016592 254072 174940 29552 657052 762520
Swap: 508292 0 508292
```