rootfs/etc/pam.d: allow all users that can log in as root

Signed-off-by: Adam Wujek <adam.wujek@cern.ch>

userspace/rootfs_override/etc/pam.d/sudo

+# accept all users who managed to log
+auth        sufficient   pam_permit.so
 auth        sufficient   pam_rootok.so
 auth        required     pam_wheel.so use_uid
 auth        required     pam_env.so