Currently, the c2s_timeout varible is not set, so misbehaving clients will stay connected, 'till TCP do them apart (https://github.com/dino/dino/issues/208).
Please set the value to a conservative, sane default. My suggestion would be:
c2s_timeout = 300
This should prevent long-hanging / dead clients, while allowing even a mobile client on the move with a horrible connection to authenticate in time.