errata: "Liberty" moniker used inappropriately in saml-sec-consider-2.0-os

In saml-sec-consider-2.0-os  section 7.1.1.9 Impersonation without
Reauthentication, there is following sentence at line 964...

   > Cookies posted by identity providers MAY be used to support
   > this validation process, though Liberty does not mandate a
   > cookie-based approach.

Note use of "Liberty" moniker.

Suggested rewrite:

   > Cookies posted by identity providers MAY be used to support
   > this validation process, though SAML 2.0 does not mandate a
   > cookie-based approach.


=JeffH