Closed connections are not refreshed in client.py _send

[requiel20]

Describe the bug
_get_conn refreshes closed connections but _send doesn't use _get_conn so it will try to send data over a connections that got closed e.g. due to being idle for too long.

This results in

Error sending OffsetCommitRequest_v2 to node 11 [KafkaConnectionError: Connection at ... closed] -- marking coordinator dead

for our use case.

Expected behaviour
_send should refresh closed connections

Environment

• aiokafka version 0.12.0

[vmaurin]

@requiel20 Any chance you can have a "DEBUG" level log in this situation ? In the client, "send" is calling "ready" that should make sure there is a living connection for the specific node that is being targeted