Redundant parameters in api-ref:domain-config

If URI specifies group and option, the request body will just
be a dict containing the option and its value, so the identity
and ldap groups are not needed in the request parameters.

Change-Id: If578cd1034482c49185675a9732fd7b4638aed7a

api-ref/source/v3/domains-config-v3.inc

@@ -278,10 +278,7 @@ Parameters
    - option: option
    - url: domain_url
    - driver: domain_driver
-   - ldap: domain_ldap
-   - config: domain_config
    - user_tree_dn: domain_user_tree_dn
-   - identity: identity
 
 Example
 ~~~~~~~
@@ -798,4 +795,4 @@ Status Codes
    - 409
    - 413
    - 415
-   - 503
+   - 503