Ambassador 0.50.0-ea5 upstream certs are offered to client

[n1koo]

Describe the bug
When using MTLS the certs that should be used for upstream are offered to the client.

Example config with Istio:

      apiVersion: ambassador/v0
      kind: Module
      name: tls
      config:
        server:
          enabled: true
          redirect_cleartext_from: 8080
          secret: ambassador-certs
        client:
          enabled: false
        upstream:
          cert_chain_file: /etc/istiocerts/cert-chain.pem
          private_key_file: /etc/istiocerts/key.pem

This is also somehow related to #981 , eg., if I remove redirect_cleartext_from: 8080 it works again. Doesn't matter if the http or https endpoint is hit.

To Reproduce
Add upstream certs, hit any TLS enabled endpoint

Expected behavior
server.secret should be used to match correct cert

Versions (please complete the following information):

• Ambassador: 0.50.0-ea5
• Bare metal Kubernetes 1.12.0

Additional context
Add any other context about the problem here.

[concaf]

@n1koo this should have been fixed in #1037 #1042, can you confirm?

[kflynn]

Closing fixed in -rc1; @n1koo please reopen if you have trouble!