feat(template): add reject empty host

template/block/reject-empty-host.conf

@@ -0,0 +1,7 @@
+# Nginx UI Template Start
+name = "Reject Empty Host"
+author = "@leic4u"
+description = { en = "Reject for unknown server_name to prevent malicious DNS, can only be used this template in default server(server_name _).", zh_CN = "拒绝空主机头，防止其他域名恶意解析，只能在 default server(server_name _) 中使用才有效。"}
+# Nginx UI Template End
+
+return 500;