changing the 82_gdm_guest_session.patch as below fixes the issue:
+ if (show_guest && access ("/usr/share/gdm/guest-session/guest-session-launch", X_OK) == 0 -+ && geteuid() >= 500) ++ && geteuid() >= 500 && !g_getenv ("LTSP_CLIENT"))
changing the 82_gdm_ guest_session. patch as below fixes the issue:
+ if (show_guest && access ("/usr/ share/gdm/ guest-session/ guest-session- launch" , X_OK) == 0
-+ && geteuid() >= 500)
++ && geteuid() >= 500 && !g_getenv ("LTSP_CLIENT"))