Revert "main/nginx: move /var/lib/nginx/tmp to /var/tmp/nginx"
FHS-3.0 says that /var/tmp should survive reboots, but for it is common practice to ignore FHS for security reasons and wipe dirs that are world writable. There is no good reason to store nginx data under a world writable directory, so move it back to /var/lib/nginx/tmp. Other distros does something similar. fixes #9246 fixes #10258 ref #9364 This reverts commit d6d624a1.