[EzPC] Modulo returns wrong result

Hi, I noticed that the modulo operator does not seem to work as expected when using arithmetic shares.
Here is an example:

```
def void main(){
    int32_al a = 42;
    int32_al b = 4;
    output(CLIENT, a % b);
}
```

This returns a seemingly random number.
The program works as expected when using `int32_bl` or `int32_pl`.

Thank you for looking into this!