unix+vms wizard mode feedback (trunk only)

The message "only user <foo> may use wizard mode" formerly given
by the Unix and VMS ports was inadvertently rendered impossible to be
delivered when authorize_wizard_mode() was added to xxxmain.c nearly
3 years ago.

sys/unix/unixmain.c

@@ -575,6 +575,7 @@ authorize_wizard_mode()
 #endif
 	if (pw && !strcmp(pw->pw_name, WIZARD_NAME)) return TRUE;
 #endif	/* WIZARD */
+	wiz_error_flag = TRUE;	/* not being allowed into wizard mode */
 	return FALSE;
 }