如 include $document_root/aaa.txt; 会报错误open() "/etc/nginx/$document_root/aaa.txt" failed (2: No such file or directory) in /etc/nginx/nginx.conf:xxx include后面的变量并未被解析
logs bind() to 0.0.0.0:80 failed (10013: An attempt was made to access a socket in a way forbidden by its access permissions) 这里发现是因为 system占用80端口、system为系统进程，又不能关闭，怎样才能...
