nginx server cannot restart using service nginx start
<p>This is my error.log</p>

<pre><code>2016/07/01 07:38:17 [emerg] 30759#0: getpwnam("nginx") failed in /etc/nginx/nginx.conf:5
2016/07/01 07:48:02 [emerg] 30806#0: getpwnam("nginx") failed in /etc/nginx/nginx.conf:5
2016/07/01 07:48:44 [emerg] 30832#0: getpwnam("nginx") failed in /etc/nginx/nginx.conf:5
2016/07/01 08:07:36 [emerg] 30913#0: getpwnam("nginx") failed in /etc/nginx/nginx.conf:5
2016/07/01 08:07:44 [emerg] 30939#0: getpwnam("nginx") failed in /etc/nginx/nginx.conf:5
2016/07/01 08:07:49 [emerg] 30964#0: getpwnam("nginx") failed in /etc/nginx/nginx.conf:5
2016/07/01 08:13:54 [emerg] 31138#0: getpwnam("nginx") failed in /etc/nginx/nginx.conf:5
2016/07/01 09:52:49 [emerg] 31735#0: getpwnam("nginx") failed
</code></pre>

<p>And this is my nginx.conf</p>

<pre><code>worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;

events {
    worker_connections 1024;
}

http {
    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;

    sendfile            on;
    tcp_nopush          on;
    tcp_nodelay         on;
    keepalive_timeout   65;
    types_hash_max_size 2048;

    include             /etc/nginx/mime.types;
    default_type        application/octet-stream;
    include /etc/nginx/conf.d/*.conf;
    server {
    listen       80 default_server;
    listen       [::]:80 default_server;
        server_name  _;
        root         /usr/share/nginx/html;
        include /etc/nginx/default.d/*.conf;
        location / {
        }
    error_page 404 /404.html;
            location = /40x.html {
        }

    error_page 500 502 503 504 /50x.html;
            location = /50x.html {
        }
    }
}
</code></pre>