Workaround for gophercloud.ServerById crashing, fixes #1257

gophercloud.ServerById is broken in v0.1.0 - it will crash if you feed it a
non-existing server ID (see [rackspace/gophercloud #168](https://github.com/rackspace/gophercloud/issues/168))

Instead, list all servers and iterate over them. If the server id isn't found,
return "DELETED" as a state. Not perfect but it works until next version of
gophercloud is released.

builder/openstack/server.go

@@ -33,12 +33,22 @@ type StateChangeConf struct {
 // an openstacn server.
 func ServerStateRefreshFunc(csp gophercloud.CloudServersProvider, s *gophercloud.Server) StateRefreshFunc {
 	return func() (interface{}, string, int, error) {
-		resp, err := csp.ServerById(s.Id)
+		servers, err := csp.ListServers()
 		if err != nil {
 			log.Printf("Error on ServerStateRefresh: %s", err)
 			return nil, "", 0, err
 		}
-
+		var resp *gophercloud.Server
+		found := false
+		for _, server := range servers {
+			if server.Id == s.Id {
+				found = true
+				resp = &server
+			}
+		}
+		if found == false {
+			return nil, "DELETED", 0, nil
+		}
 		return resp, resp.Status, resp.Progress, nil
 	}
 }