Protect against buffer overflows in parse_message.
Protect against buffer overflows in parse_message.

jech/dht,loadletter/dht256,tempbottle/dht-1,mikedld/dht,Librevault/dht,raspopov/dht,cfpp2p/dht,Erkan-Yilmaz/dht,gabrielfalcao/dht