fix removing old raft server

weed/shell/command_raft_server_remove.go

@@ -41,7 +41,8 @@ func (c *commandRaftServerRemove) Do(args []string, commandEnv *CommandEnv, writ
 
 	err = commandEnv.MasterClient.WithClient(false, func(client master_pb.SeaweedClient) error {
 		_, err := client.RaftRemoveServer(context.Background(), &master_pb.RaftRemoveServerRequest{
-			Id: *serverId,
+			Id:    *serverId,
+			Force: true,
 		})
 		if err != nil {
 			return fmt.Errorf("raft remove server: %v", err)