HHVM 的 Nginx 配置 SSL 后 HTTP 不可用

HHVM 的 Nginx 配置 SSL 后 HTTP 不可用，但是 HTTPS 是正常的。

HTTP 访问后错误：
400 Bad Request
The plain HTTP request was sent to HTTPS port

HTTP 也无法通过

if ($scheme = http) {
    return 301 https://$server_name$request_uri;
}

强制跳转为 HTTPS，感觉开了 HTTPS，HTTP 就是废的。

请问怎么解决？

site-enable 里面的 default 配置文件 include 了的 hhvm.conf 内容如下

location ~ \.(hh|php)$ {
    fastcgi_keep_conn on;
    fastcgi_pass unix:/var/run/hhvm/hhvm.sock;
    fastcgi_index  index.php;
    fastcgi_param  SCRIPT_FILENAME $document_root$fastcgi_script_name;
    include        fastcgi_params;
}

default 配置文件如下

server {
listen 80;
listen 443 ssl;

root /usr/share/nginx/html;
index index.html index.htm index.php;

server_name wlppr.net;

ssl on;
ssl_certificate /etc/nginx/ssl/wlppr_net.crt;
ssl_certificate_key /etc/nginx/ssl/wlppr_net.key;

include hhvm.conf;

location / {

    try_files $uri $uri/ =404;

}

}