DOCSP-27671 no kerberos support in atlas (#3176)

Author: Dave Cuthbert

source/core/authentication.txt

@@ -81,12 +81,10 @@ Kerberos Authentication
 
 `MongoDB Enterprise
 <http://www.mongodb.com/products/mongodb-enterprise-advanced?tck=docs_server>`_
-and `MongoDB Atlas
-<https://www.mongodb.com/cloud/atlas?tck=docs_server>`__ support
-:ref:`Kerberos Authentication <security-kerberos>`. Kerberos is an industry
-standard authentication protocol for large client/server systems that
-provides authentication using short-lived tokens that are called
-tickets.
+supports :ref:`Kerberos Authentication <security-kerberos>`. Kerberos is
+an industry standard authentication protocol for large client/server
+systems that provides authentication using short-lived tokens that are
+called tickets.
 
 To use MongoDB with Kerberos, you must have a properly configured
 Kerberos deployment, configured :ref:`Kerberos service principals