Missing default value of createrole_self_grant in document

From e1c64376c464e7da22171f0e0e3a7f44309eccff Mon Sep 17 00:00:00 2001
From: Shi Yu <shiy.fnst@fujitsu.com>
Date: Thu, 16 Feb 2023 17:19:24 +0800
Subject: [PATCH v1] Add default value of createrole_self_grant in document

---
 doc/src/sgml/config.sgml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index ecd9aa73ef..e5c41cc6c6 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -9499,7 +9499,8 @@ SET XML OPTION { DOCUMENT | CONTENT };
         is set to a non-empty value, the newly-created role will be granted
         to the creating user with the options specified. The value must be
         <literal>set</literal>, <literal>inherit</literal>, or a
-        comma-separated list of these.
+        comma-separated list of these. The default value is an empty string,
+        which disables the feature.
        </para>
        <para>
         The purpose of this option is to allow a <literal>CREATEROLE</literal>
-- 
2.30.0.windows.2