Previously, tcp listener perform synchronous proxy protocol header
read during connection accept. It could significantly reduce vmauth
performance and lead to timeout at serving http requests.
This commit changes this logic and performs proxy protocol header
parsing during first Read request from connection or RemoteAddr method
call. It significantly improves performance and reduce possible
bottleneck at connections accept method.
Related PR https://github.com/VictoriaMetrics/VictoriaMetrics/pull/9546/