Bug 21997

Description of problem: 
When in a root(#) terminal (via using "su -"), when in a gnome (wayland) session, attempting to invoke MCC presents an ncurses drakconf menu. 
This does not happen when using the "su" root(#) terminal, the expected Mageia Control Centre is presented
If invoking MCC from a user terminal ($), after a request for administrator password, the expected Mageia Control Centre is presented.
With all menu launchers the expected Mageia Control Centre is presented.

I have attempted using :  xhost +si:localuser:root 
and: export DISPLAY=:0

these appear to have no effect.


Version-Release number of selected component (if applicable):


How reproducible: every time


Steps to Reproduce:
1. upgrade an up-to-date Mga6 Gnome system to Cauldron, either real hardware or in a Virtual-box machine.
2: reboot and choose Gnome (Wayland) session and login
3.invoke a user terminal and attempt to launch mcc. an administrator password authentification dialogue is presented, enter the admin password and Mageia Control Centre is presented. close the MCC window
4. change to a root(#) prompt using "su", and invoke mcc. the expected Mageia Control Centre is presented. close the MCC window.
5. exit the root(#) terminal, then change back to a root(#) prompt using "su -".
 invoke mcc and the ncurses drakconf menu is presented