RqMultipart.Base incorrect handles non-printable ASCII characters
RqMultipart.Base incorrect handles non-printable ASCII characters
to reproduce it just make a small changes in `RqMultipartTest.handlesRequestInTime()`
https://github.com/yegor256/takes/blob/master/src/test/java/org/takes/rq/RqMultipartTest.java#L357

change 

```
for (int ind = 0; ind < length; ++ind) {
            bwr.write("X");
}
```

to

```
Random rnd = new Random();
for (int ind = 0; ind < length; ++ind) {
    bwr.write(String.format("%c", rnd.nextInt(128)));         
}
```

`bwr.write(String.format("%c", rnd.nextInt(108)+20));` will work fine.
so problem in the non-printable characters from 0 to 19
