Allow "finished flushing" during v3 handshake

src/or/connection_or.c

@@ -439,6 +439,7 @@ connection_or_finished_flushing(or_connection_t *conn)
     case OR_CONN_STATE_PROXY_HANDSHAKING:
     case OR_CONN_STATE_OPEN:
     case OR_CONN_STATE_OR_HANDSHAKING_V2:
+    case OR_CONN_STATE_OR_HANDSHAKING_V3:
       break;
     default:
       log_err(LD_BUG,"Called in unexpected state %d.", conn->_base.state);