const net/http/internal/http2.initialMaxConcurrentStreams

2 uses

	net/http/internal/http2 (current package)
		transport.go#L57: 	initialMaxConcurrentStreams = 100
		transport.go#L622: 		maxConcurrentStreams:        initialMaxConcurrentStreams, // "infinite", per spec. Use a smaller value until we have received server settings.