From coverity: possible memory leak. (CID 1547857)

*** CID 1547857:  Resource leaks  (RESOURCE_LEAK)
/src/core/or/connection_edge.c: 4239 in connection_exit_begin_resolve()
4233         case DOS_STREAM_DEFENSE_NONE:
4234           break;
4235         case DOS_STREAM_DEFENSE_REFUSE_STREAM:
4236           dns_send_resolved_error_cell(dummy_conn, RESOLVED_TYPE_ERROR_TRANSIENT);
4237           return 0;
4238         case DOS_STREAM_DEFENSE_CLOSE_CIRCUIT:
>>>     CID 1547857:  Resource leaks  (RESOURCE_LEAK)
>>>     Variable "dummy_conn" going out of scope leaks the storage it points to.
4239           return -END_CIRC_REASON_RESOURCELIMIT;
4240       }
4241     
4242       /* send it off to the gethostbyname farm */
4243       switch (dns_resolve(dummy_conn)) {
4244         case -1: /* Impossible to resolve; a resolved cell was sent. */