[FAB-4284] - Fix link to CA Overview

[ci-skip]

Change-Id: I94a8758e09bb3268c2853e050acfd0903cd536c9
Signed-off-by: Nick Gaski <ngaski@us.ibm.com>

docs/index.md

@@ -15,7 +15,7 @@ Applications can be developed to interact with the blockchain network on behalf
 ### How Different Components of the Fabric Work Together
 The [Transaction Flow](http://hyperledger-fabric.readthedocs.io/en/latest/txflow.html) document provides an excellent description of the application/SDK, peers, and orderers working together to process transactions and producing blocks.
 
-Security on the Fabric is enforced with digital signatures. All requests made to the fabric must be signed by users with appropriate enrollment certificates. For a user's enrollment certificate to be considered valid on the Fabric, it must be signed by a trusted Certificate Authority (CA). Fabric supports any standard CAs. In addition, Fabric provides a CA server. See this [overview](http://hyperledger-fabric.readthedocs.io/en/latest/Setup/ca-setup.html#overview).
+Security on the Fabric is enforced with digital signatures. All requests made to the fabric must be signed by users with appropriate enrollment certificates. For a user's enrollment certificate to be considered valid on the Fabric, it must be signed by a trusted Certificate Authority (CA). Fabric supports any standard CAs. In addition, Fabric provides a CA server. See this [overview](http://hyperledger-fabric-ca.readthedocs.io/en/latest/users-guide.html#overview).
 
 ### Features of the SDK for Node.js
 The Hyperledger Fabric SDK for Node.js is designed in an Object-Oriented programming style. Its modular construction enables application developers to plug in alternative implementations of key functions such as crypto suites, the state persistence store, and logging utility.