s3-netlogon: Fix NETLOGON credential chain. Fixes Bug #6099 (Windows 7 joining Samba3...

s3-netlogon: Fix NETLOGON credential chain. Fixes Bug #6099 (Windows 7 joining Samba3) and probably many, many more.

Jeremy, with 9a5d5cc1db0ee60486f932e34cd7961b90c70a56 you alter the in negotiate
flags (which are a pointer to the out negotiate flags assigned in the generated
netlogon server code). So, while you wanted to just set the *out* negflags, you
did in fact reset the *in* negflags, effectively eliminating the
NETLOGON_NEG_STRONG_KEYS bit (formerly known as NETLOGON_NEG_128BIT) which then
caused creds_server_init() to generate 64bit creds instead of 128bit, causing
the whole chain to break. *Please* check.

Guenther