Handle a null ServerConfig

serverutil/http.go

@@ -30,6 +30,7 @@ type ServerConfig struct {
 // SIGINT or SIGTERM and return nil.
 func Serve(h http.Handler, serverConfig *ServerConfig, addr string) (err error) {
 	var tlsConfig *tls.Config
+	if serverConfig != nil {
 		if serverConfig.TLS != nil {
 			tlsConfig, err = serverConfig.TLS.TLSConfig()
 			if err != nil {
@@ -44,6 +45,7 @@ func Serve(h http.Handler, serverConfig *ServerConfig, addr string) (err error)
 		if serverConfig.MaxInflightRequests > 0 {
 			h = newLoadSheddingWrapper(serverConfig.MaxInflightRequests, h)
 		}
+	}
 
 	srv := &http.Server{
 		Addr:         addr,