add Comment for HTTP basic authentication.

nginx-ldap-auth.conf

@@ -23,6 +23,8 @@ http {
             auth_request /auth-proxy;
 
             # redirect 401 to login form
+            # Comment them out if using HTTP basic authentication.
+            # or authentication popup won't show
             error_page 401 =200 /login;
 
             proxy_pass http://backend/;