event: Handshake Client Error ExceededTimeLimit duration

Cardano-node with 1.12.0 was switched to use systemd socket activation. This means that the socket is created prior to the node being up and running. Everything works if the node comes up in 10 seconds, but if it doesn't (for example with an unclean shutdown), db-sync will give up trying and exit after 10 seconds. I think this should log the message and keep trying with exponential back-off.