Remove default port

Signed-off-by: Ethan Gallant <ethan.gallant@gmail.com>

web/tls_config.go

@@ -216,7 +216,7 @@ func ListenAndServe(server *http.Server, flags *FlagConfig, logger log.Logger) e
  }
 
  if flags.WebListenAddresses == nil {
- *flags.WebListenAddresses = []string{":9090"}
+ return errors.New("no valid WebListenAddress specified")
  }
 
  listeners := make([]net.Listener, 0, len(*flags.WebListenAddresses))