GSS-NTLMSSP vulnerable to memory leak when parsing usernames

GSS-NTLMSSP is a mechglue plugin for the GSSAPI library that implements NTLM authentication. Prior to version 1.2.0, a memory leak can be triggered when parsing usernames which can trigger a denial-of-service. The domain portion of a username may be overridden causing an allocated memory area the size of the domain name to be leaked. An attacker can leak memory via the main `gss_accept_sec_context` entry point, potentially causing a denial-of-service. This issue is fixed in version 1.2.0.