To reproduce:

• Start GossipRouter
• Start 2 Draws with tunnel.xml, connecting to the GR
• Paint a bit in the 2 windows, to generate messages (and thus change the digests)
• Kill GR
• When both Draw instances become cluster singletons, start GR again
  ==> Observe that we get messages that indicate a requested retransmission couldn't be satisfied because the message was not found:
  14:38:16,203 [WARN] [OOB Thread,demo,192.168.5.2:4397] NAKACK.handleMessage(): 192.168.5.2:4397] discarded message from non-member 192.168.5.2:4393, my view is [192.168.5.2:4397|2] [192.168.5.2:4397]
  14:38:16,890 [WARN] [OOB Thread,demo,192.168.5.2:4393] NAKACK.handleMessage(): 192.168.5.2:4393] discarded message from non-member 192.168.5.2:4397, my view is [192.168.5.2:4393|2] [192.168.5.2:4393]