[Ubuntu] sudoers file seems to disappear during an update

[Bischoff]

(Moved from openmainframeproject/feilong#856)

Recently, sdkserver crashed with this as part of the python traceback:

Feb 04 14:08:27 feilong sudo[12810]: pam_unix(sudo:auth): auth could not identify password for [zvmsdk] 

Indeed, file /etc/sudoers.d/sudoers-zvmsdk was missing, while it used to be there.

Since I did an apt-get update recently, I am wondering if the post-remove script is called after the post-install script of the new version of zvmsdk package.

Recreating the file works around the issue, but it's a problem if we have to do this at each update.