rootlogout.sh => download
 #!/bin/sh
gawk '{gsub(/#auth       required    pam_succeed_if.so user != root quiet/,
       "auth       required    pam_succeed_if.so user != root quiet"); print; }' /etc/pam.d/gdm > /etc/pam.d/gdm.bak
gawk '{gsub(/#auth        required      pam_succeed_if.so user != root quiet/,
       "auth        required      pam_succeed_if.so user != root quiet"); print; }' /etc/pam.d/gdm-password > /etc/pam.d/gdm-password.bak
mv -f /etc/pam.d/gdm.bak /etc/pam.d/gdm
mv -f /etc/pam.d/gdm-password.bak /etc/pam.d/gdm-password