add auth.proxy headers to sample.ini

conf/sample.ini

@@ -294,6 +294,7 @@ log_queries =
 ;auto_sign_up = true
 ;ldap_sync_ttl = 60
 ;whitelist = 192.168.1.1, 192.168.2.1
+;headers = Email:X-User-Email, Name:X-User-Name
 
 #################################### Basic Auth ##########################
 [auth.basic]