用 opennssl 指令方法檢查網站是否有 h2 , spdy

openssl s_client -connect facebook.com:443 -nextprotoneg ''

CONNECTED(00000003)
Protocols advertised by server: h2, h2-fb, spdy/3.1-fb-0.5, spdy/3.1, spdy/3, http/1.1