packer build failure the user account for flask app doesn't exist at build time

[jprorama]

The reggie user currently used as the process and file system owner for the flask app doesn't exist at build time causing the packer build to fail.

For security reasons this app should run as an unprivileged user and not have write access to anything but log files in /var/log/user_reg (which could be symlink from the app dir if desired).