kat-client: Don't couple so many TLS settings together
kat-client: Don't couple so many TLS settings together

 - It only obeyed `ca_cert` if `insecure==true`
 - It only obeyed `minTLSv`      if `headers["Host"] != "" && sni==true`
 - It only obeyed `maxTLSv`      if `headers["Host"] != "" && sni==true`
 - It only obeyed `cipherSuites` if `headers["Host"] != "" && sni==true`
 - It only obeyed `ecdhCurves`   if `headers["Host"] != "" && sni==true`

datawire/ambassador,datawire/ambassador,datawire/ambassador,datawire/ambassador,datawire/ambassador