Added cert negotiation clarification

Author: vladvino

articles/api-management/self-hosted-gateway-overview.md

@@ -47,7 +47,7 @@ The following functionality found in the managed gateways is **not available** i
 - Validation of server and client certificates using CA root certificates uploaded to API Management service. To add support for custom CA, add a layer to the self-hosted gateway container image that installs the CA's root certificate.
 - Integration with the [Service Fabric](../service-fabric/service-fabric-api-management-overview.md)
 - TLS session resumption
-- Client certificate renegotiation. Therefore, when using client certificate authentication, clients must be required to present their certificates as part of the TLS handshake.
+- Client certificate negotiation. This means that API consumers must present their certificates as part of the initial TLS handshake. To accomplish that, enable the negotiate client certificate setting when configuring a self-hosted gateway custom hostname.
 - Built-in cache. See this [document](api-management-howto-cache-external.md) to learn about using external cache in self-hosted gateways.
 
 ## Connectivity to Azure