Start nginx worker process with same user as master process

[Sushma]

Thanks a lot Francis. 
Apparently nginx was once started as root. So automatically the ownership of
the temp folders got changed to nginx user.
This explains the sudden permission change even though I had set it
explictly.
Thanks for your help.

Cheers,
Sushma

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,269006,269745#msg-269745