HTTPS proxy hangs during stress test

[sausagenoods]

Hello, I implemented a forward HTTPS proxy using this library. When I test using ab-proxy, it always hangs during the test. Here is the relevant section of the code:

func main() {
        loadConfig()
        authCache, _ = bigcache.NewBigCache(bigcache.DefaultConfig(c.credCacheTTL))
        proxy := goproxy.NewProxyHttpServer()
        proxy.Tr.MaxIdleConns = 0
        proxy.Tr.MaxConnsPerHost = 0
        proxy.Tr.MaxIdleConnsPerHost = 0
        proxy.Verbose = c.verbose
        s := &http.Server{
                Addr: c.bindAddr,
                Handler: proxy,
                TLSNextProto: make(map[string]func(*http.Server, *tls.Conn, http.Handler)),
        }
        log.Fatal(s.ListenAndServeTLS(c.certFile, c.keyFile))
}

Here is the command I'm using to test:
./ab-proxy -c 20 -n 5000 --proxy 'https://user:pass@myproxyserver.domain' 'https://syd1.speedtest.telstra.net:8080/download?size=10485760'
It makes 5000 GET requests to download 10 MiB from a server using 20 threads through the proxy server.

When I import a fork of this library instead without changing anything in the code, it no longer hangs and works fine.