Fix for magneto fix that still kept hanging sometimes

Plz Wait till 20141210 before (maybe) honoring pull request, needs re-test with current master, maybe the other code "MAXRETRY etc". made it anyhow work 100%. Will be tested 5 different ARdrone2 with a good history of flying and misuse.
why sending 10 times, is it some statistical experience or do you have intel that it has to done like this ?
if it works in the end I'm perfectly fine with this!