Nginx pass blocked referrers

Question

I all time receiving bot spam, so I block bots using this.

I'm very surprized but I still receive emails from Django, that requests pass Nginx.

Amount of email decreased from thousands per hour to tens per hour but from same referrers.

[Django] ERROR (EXTERNAL IP): Invalid HTTP_HOST header: 'www.elong.com'. You may need to add 'www.elong.com' to ALLOWED_HOSTS.

My blacklist looks:

map $http_referer $bad_referer {
    hostnames;

    default                             0;

    # Put regexes for undesired referers here
    "*.cn"                              1;
    "~bitauto.com"                      1;
    "~hunantv.com"                      1;
    ...
    "~com.cn"                           1;
    "~sogou.com"                        1;
    "~sina.com.cn"                      1;
    "~weibo.com"                        1;
    ...
    "~114la.com"                        1;
    "~quer.com"                         1;
    "~elong.com"                        1;
    "~yninfo.com"                       1;
    "~news.cn"                          1;
    "~126.com"                          1;
    "~pcpop.com"                        1;

}

If I make curl everything works:

curl --referer http://www.qunar.com my-host.com
curl: (52) Empty reply from server


curl --referer sina.com.cn my-host.com
curl: (52) Empty reply from server