[FAB-5740] Remove TCerts from documentation

Remove TCerts from the fabric CA documentation in order to
avoid confusion that TCerts are supported in fabric.
It will be added back when one or more SDKs support it.

Change-Id: Idea62aa9306496286c196a4f62fadf18073ca442
Signed-off-by: Keith Smith <bksmith@us.ibm.com>

docs/source/users-guide.rst

@@ -9,9 +9,6 @@ It provides features such as:
   * registration of identities, or connects to LDAP as the user
     registry
   * issuance of Enrollment Certificates (ECerts)
-  * issuance of Transaction Certificates (TCerts), providing both
-    anonymity and unlinkability when transacting on a Hyperledger Fabric
-    blockchain
   * certificate renewal and revocation
 
 Hyperledger Fabric CA consists of both a server and a client component as
@@ -791,19 +788,6 @@ When LDAP is configured, enrollment works as follows:
    password. If the LDAP bind is successful, the enrollment processing is
    authorized and can proceed.
 
-When LDAP is configured, attribute retrieval works as follows:
-
-
--  A client SDK sends a request for a batch of tcerts **with one or more
-   attributes** to the Fabric CA server.
--  The Fabric CA server receives the tcert request and does as follows:
-
-   -  extracts the enrollment ID from the token in the authorization
-      header (after validating the token);
-   -  does an LDAP search/query to the LDAP server, requesting all of
-      the attribute names received in the tcert request;
-   -  the attribute values are placed in the tcert as normal.
-
 Setting up a cluster
 ~~~~~~~~~~~~~~~~~~~~