To reproduce:

1. Forwarder
   $ hicn-light-daemon --log trace
2. Ping server 1
   $ GLOG_v=4 hicn-ping-server -V -n b001::/64
3. Ping server 2
   $ GLOG_v=4 hicn-ping-server -V -n b002::/64
4. Ping client
   $ GLOG_v=4 ./build-root/bin/hicn-ping-client -V -m 7

Problem: The client asks for `b001::/64` but one of the replies comes from server 2 (b002::/64).