update markdown for ALTER USER PRIVILEGE

documentation20/webdocs/markdowndocs/administrator-ch.md

@@ -250,10 +250,10 @@ ALTER USER <user_name> PASS <'password'>;
 修改用户密码, 为避免被转换为小写，密码需要用单引号引用,单引号为英文半角
 
 ```
-ALTER USER <user_name> PRIVILEDGE <'super'|'write'|'read'>;
+ALTER USER <user_name> PRIVILEDGE <super|write|read>;
 ```
 
-修改用户权限为：super/write/read。 为避免被转换为小写，密码需要用单引号引用,单引号为英文半角
+修改用户权限为：super/write/read，不需要添加单引号
 
 ```
 SHOW USERS;