关键：nginx.conf
try_files $uri $uri/ /index.php$is_args$args;
https://docs.nextcloud.com/server/12/admin_manual/installation/source_installation.html#prerequisites-label
https://segmentfault.com/a/1190000008456241
http://baijiahao.baidu.com/s?id=1573550374157961&wfr=spider&for=pc
https://docs.nextcloud.com/server/12/admin_manual/installation/nginx.html#nextcloud-in-the-webroot-of-nginx
