api-ref: add config_drive to 2.75 rebuild response parameters

Change I9d257a003d315b84b937dcef91f3cb41f3e24b53 and the 2.75
microversion returns the config_drive parameter in the rebuild
response and it's in the 2.75 rebuild response sample but was
missing from the response parameters table.

Change-Id: I89eca8638bc0d64b7f320f4ec5c49375bfebdb56

api-ref/source/parameters.yaml

@@ -2042,6 +2042,15 @@ config_drive_resp:
   in: body
   required: true
   type: string
+config_drive_resp_rebuild:
+  description: |
+    Indicates whether or not a config drive was used for this server.
+    The value is ``True`` or an empty string. An empty string stands for
+    ``False``.
+  in: body
+  required: true
+  type: string
+  min_version: 2.75
 configure_project_cloudpipe:
   description: |
     VPN IP and Port information to configure the cloudpipe instance..

api-ref/source/servers-actions.inc

@@ -634,6 +634,7 @@ Response
   - trusted_image_certificates: server_trusted_image_certificates_resp
   - server_groups: server_groups_2_71
   - locked_reason: locked_reason_resp
+  - config_drive: config_drive_resp_rebuild
   - OS-EXT-AZ:availability_zone: OS-EXT-AZ:availability_zone_update_rebuild
   - OS-EXT-SRV-ATTR:host: OS-EXT-SRV-ATTR:host_update_rebuild
   - OS-EXT-SRV-ATTR:hypervisor_hostname: OS-EXT-SRV-ATTR:hypervisor_hostname_update_rebuild