[OWL-1018][backend] Add `trash` back to `Makefile`
[OWL-1018][backend] Add `trash` back to `Makefile`

f5d27fb was a mistake. In our `docker` environment, we still need
`trash` in `Makefile` because we are not using `configure`.

Cepave/open-falcon-backend,masato25/open-falcon-backend,masato25/open-falcon-backend,Cepave/open-falcon-backend,masato25/open-falcon-backend,masato25/open-falcon-backend,masato25/open-falcon-backend,Cepave/open-falcon-backend,masato25/open-falcon-backend,Cepave/open-falcon-backend,Cepave/open-falcon-backend,Cepave/open-falcon-backend