Update default.cfg

Add reasonable example for LDAP attributes and fix ldap_server req.

default.cfg

@@ -18,10 +18,13 @@
 ; rest_poll_interval=1
 
 [starling_auto_provision]
-# To turn on auto-provisioning, you have to specify both attributes.
+# To turn on auto-provisioning, you have to specify both attributes,
+# and also configure an LDAP server policy name in [ldap_server].
 
 # The LDAP attribute name of the user's email address.
 ; email_attribute=<LDAP-attribute-of-user-email-address>
+# For example:
+; email_attribute=mail
 
 # The LDAP attribute name of the user's phone number.
 # Make sure that the phone numbers in LDAP adhere to the following formatting rules:
@@ -31,6 +34,8 @@
 # that is, must not include hyphen (-), space, or any other separator characters.
 # Otherwise, SPS cannot parse the phone number and therefore authentication will be unsuccessful
 ; phone_attribute=<LDAP-attribute-of-user-phone-number>
+# For example:
+; phone_attribute=mobile
 
 ###### Common plugin options ######
 # To enable or change a parameter, uncomment its line by removing the ';'