bug: Send Queue full

[erhant]

With v0.3 we have moved to latest branch of libp2p, instead of our fork which was out-dated.

[WARN  libp2p_gossipsub::behaviour] Send Queue full. Could not send IDontWant(IDontWant { message_ids: [MessageId(d70001e518f515ee)] }).

This happens when we do pongs in compute node.

[erhant]

1. behaviour.rs#L2841 is where we get the Send Queue full. ... message.
2. rpc.rs#L82 the error is returned here due to len >= self.priority_cap check
3. rpc.rs#L49 priority_cap: cap / 2 is set here
4. Sender::new is alays called with self.config.connection_handler_queue_len() (see behaviour.rs#L3119 and [behaviour.rs#L3092
5. connection_handler_queue_len is given via config builder function connection_handler_queue_len so it is directly related to this error

Giving a larger value for this increases the memory usage.