Change to temporary redirect

When exposed via a tunnel, if the underlying service is
switched, the browser remembers the / => /ui redirection
so this can be changed to a temporary redirect.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alex@openfaas.com>

gateway/main.go

@@ -256,7 +256,7 @@ func main() {
 	r.HandleFunc("/healthz",
 		handlers.MakeForwardingProxyHandler(reverseProxy, forwardingNotifiers, urlResolver, nilURLTransformer, serviceAuthInjector)).Methods(http.MethodGet)
 
-	r.Handle("/", http.RedirectHandler("/ui/", http.StatusMovedPermanently)).Methods(http.MethodGet)
+	r.Handle("/", http.RedirectHandler("/ui/", http.StatusTemporaryRedirect)).Methods(http.MethodGet)
 
 	tcpPort := 8080