E325: ATTENTION
Found a swap file by the name ".nginx.conf.swp"
owned by: root dated: Fri Nov 1 18:42:48 2019
file name: /usr/local/nginx/conf/nginx.conf
modified: YES
user name: root host name: VM_0_2_centos
process ID: 2990 (still running)
While opening file "nginx.conf"
dated: Fri Nov 1 19:14:48 2019
NEWER than swap file!

原因：可能是由于上一次在编辑nginx.conf时，文件没有退出就直接（强行）重启或关机造成的，产生.nginx.conf.swp文件。
解决方法：在nginx.conf文件所在的目录，执行ls -a，会发现该文件，删除该文件 # rm /usr/local/nginx/conf/.nginx.conf.swp