The output below shows key_name and config_drive attributes on the basic (non-detailed) server entity. They should only be returned in a detailed server entity (/servers/detail):
$ curl -H "X-Auth-Token: admin:admin" http://localhost:8774/v1.1/admin/servers
{"servers": [{"uuid": "b62b8b5b-7126-4219-bf7a-13308e1862b8", "links": [{"href": "http://localhost:8774/v1.1/admin/servers/2", "rel": "self"}, {"href": "http://localhost:8774/admin/servers/2", "rel": "bookmark"}], "key_name": null, "name": "stacktester1", "id": 2, "config_drive": ""}, {"uuid": "1cf4680d-958d-4bdd-82b7-cd7624255577", "links": [{"href": "http://localhost:8774/v1.1/admin/servers/1", "rel": "self"}, {"href": "http://localhost:8774/admin/servers/1", "rel": "bookmark"}], "key_name": null, "name": "stacktester1", "id": 1, "config_drive": ""}]}
Looks like this bug came back.