Comment 11 for bug 1746482

After the preliminary analysis my understanding is as follows:
since the change found thanks to the bisection the behaviour change in a way that if an unsupported security mode is requested it results in an error (invalid argument in this case).

Looks like NTLM was not supported even before the change in question, it was just unnoticed since it was silently mapped to NTLMSSP.

So no actual regression in functionality is observed, but rather regression in UI being less restrictive before the kernel change.