better handling of default transport modification

pkg/requests/http.go

@@ -7,22 +7,22 @@ import (
 )
 
 type userAgentTransport struct {
-	Next      http.RoundTripper
+	next      http.RoundTripper
 	userAgent string
 }
 
 func (t *userAgentTransport) RoundTrip(req *http.Request) (*http.Response, error) {
 	r := req.Clone(req.Context())
 	setDefaultUserAgent(r.Header, t.userAgent)
-	return t.Next.RoundTrip(r)
+	return t.next.RoundTrip(r)
 }
 
-var DefaultHTTPClient = &http.Client{Transport: &DefaultTransport}
-
-var DefaultTransport = userAgentTransport{
-	Next:      http.DefaultTransport,
+var DefaultHTTPClient = &http.Client{Transport: &userAgentTransport{
+	next:      DefaultTransport,
 	userAgent: "oauth2-proxy/" + version.VERSION,
-}
+}}
+
+var DefaultTransport = http.DefaultTransport
 
 func setDefaultUserAgent(header http.Header, userAgent string) {
 	if header != nil && len(header.Values("User-Agent")) == 0 {