fast_access_perm() now returns 'error' if the conference does not exist.

src/server/membership.c

@@ -612,7 +612,10 @@ Access
 fast_access_perm(Conf_no victim)
 {
     Conf_type conf_type;
-    
+
+    if ( !cached_conf_exists(victim) )
+	return error;
+
     if ( ACTPERS != 0 && (ENA(admin, 2) || ENA(wheel,8) || ACTPERS == victim) )
     	return unlimited;