#915 Fix missing id on image creation

On image creation, ogServer always sends 0 as image id to clients. When
clients sends the response to the "create image" command with new
information to update the image's entry in the database, the image id is
0 and ogServer fails to update the image's entry.

This patch fixes this, assigning the correct id of the image.

Fixes: d2f20d0be0 ("#942 Create DB image when calling POST /image/create")

src/rest.c

@@ -2223,6 +2223,7 @@ static int og_cmd_create_image(json_t *element, struct og_msg_params *params)
 
 		snprintf(new_image_id, sizeof(new_image_id), "%u", err);
 		params->id = new_image_id;
+		json_object_set_new(element, "id", json_string(params->id));
 	}
 
 	clients = json_copy(element);