[NSWI004] heap/overhead test updated

[Vojtech Horky]

Hello,

we have updated the heap/overhead test to be a bit more liberal when 
checking the detected memory.

We have not realized that the threshold would not be sufficient once 
stacks for real threads are allocated. We hope this new setting would 
work better for you (if not, e-mail us, please).

Thanks goes to the EMINEM team for noticing this.

Cheers,
- VH