The intermediate CA certificate is signed by either another intermediate CA certificate or the root CA certificate. The root certificate is the last certificate in the chain. The certificate authority might or might not include the root certificate in the chain it returns. Webgateway does not require the root certificate. The root certificate is the certificate that web browsers need to validate your server certificate and the rest of the intermediate CA certificates in the chain.
Most web browsers come bundled with root certificates of well known certificate authorities.
In this case, replace the self-signed certificate with the certificate from the certificate authority. Webgateway to turn on SSL .