fix assert trigger in server

Jan 18 04:11:43.312 [warn] connection_edge_send_command(): no circ. Closing.

i think it was while sending a connected relay cell back.
reason for having the circ gone is still not known. presumably the end cell
arrived at just the right time.


svn:r1005

src/or/connection_edge.c

@@ -148,6 +148,8 @@ int connection_edge_send_command(connection_t *fromconn, circuit_t *circ, int re
 
   if(!circ) {
     log_fn(LOG_WARN,"no circ. Closing.");
+    assert(fromconn);
+    fromconn->marked_for_close = 1;
     return -1;
   }