[kaffe] Turn exception into warning message for ClassLoader.setSigners()

[Dalibor Topic]

Casey Marshall wrote:

Thanks a lot for the patch and thanks heaps to Mark for repeatedly 
poking me at it. I've finally checked it in. Sorry for being so slow 
with patches lately.

I hope we can use helmer's and guilhem's VMClassLoader classpath merge 
patches soon to bring us closer to what Classpath does.

cheers,
dalibor topic