Ensure NTLMv2 is still disabled
In #12974 (moved), we disabled NTLMv1 and Negotiate auth. Mozilla is also planning on deploying NTLMv2. We need to keep an eye on this deployment and its associated prefs for FF38-ESR, and set the prefs they provide in ways that make sense for Tor.
Their bug is: https://bugzilla.mozilla.org/show_bug.cgi?id=423758