/etc/nginx/sites-enabled/app:2 nginx 中不允许使用“map”指令：配置文件 /etc/nginx/nginx.conf 测试失败

Question

用户www-数据；自动worker_processes；pid /run/nginx.pid;

events {
        worker_connections 768;
        # multi_accept on;
}

http {
        # this section is needed to proxy web-socket connections
        map $http_upgrade $connection_upgrade {
                default upgrade;
                  ''      close;
        }

        ##
        # Basic Settings
        ##

        sendfile on;
        tcp_nopush on;
        tcp_nodelay on;
        keepalive_timeout 65;
        types_hash_max_size 2048;
        # server_tokens off;

        # server_names_hash_bucket_size 64;
        # server_name_in_redirect off;

        include /etc/nginx/mime.types;
        default_type application/octet-stream;

        ##
        # SSL Settings
        ##

        ssl_protocols TLSv1 TLSv1.1 TLSv1.2; # Dropping SSLv3, ref: POODLE
        ssl_prefer_server_ciphers on;

        ##
        # Logging Settings
        ##

        access_log /var/log/nginx/access.log;
        error_log /var/log/nginx/error.log;

        ##
        # Gzip Settings
        ##
        include /etc/nginx/mime.types;
        gzip on;
        gzip_disable "msie6";
        # gzip_vary on;
        # gzip_proxied any;
        # gzip_comp_level 6;
        # gzip_buffers 16 8k;
        # gzip_http_version 1.1;
        # gzip_types text/plain text/css application/json 
          application/javascript text/xml application/xml applicatio
        n/xml+rss text/javascript;
        ##
        # Virtual Host Configs
        ##
        include /etc/nginx/conf.d/*.conf;
        include /etc/nginx/sites-enabled/*;
}
#mail {
#       # See sample authentication script at:
#       # http://wiki.nginx.org/ImapAuthenticateWithApachePhpScript
# 
#       # auth_http localhost/auth.php;
#       # pop3_capabilities "TOP" "USER";
#       # imap_capabilities "IMAP4rev1" "UIDPLUS";
# 
#       server {
#               listen     localhost:110;
#               protocol   pop3;
#               proxy      on;
#       }
# 
#       server {
#               listen     localhost:143;
#               protocol   imap;
#               proxy      on;
#       }
#}
include /etc/nginx/sites-enabled/*;

使用 nginx Web 服务器部署 Meteor：这是我的 nginx.config 文件，我收到以下错误“/etc/nginx/sites-enabled/app:2 nginx: 配置文件 /etc/nginx/ 中不允许使用“map”指令执行“ sudo nginx -t ”时，nginx.conf 测试失败”