fix(webservice): Fix count behavior to make sure it’s consistent

count method would give 0 or error depending on the base used when
 searching for forbidden attributes in filter. No it will return 0 to
 match ls behavior

issue #5746

webservice/html/jsonrpc.php

@@ -207,7 +207,7 @@ class fdRPCService
     $this->checkAccess($type);
     $infos  = objects::infos($type);
     $acl    = $infos['aclCategory'].'/'.$infos['mainTab'];
-    if (strpos($ui->get_permissions($ou, $acl), 'r') !== FALSE) {
+    if ((strpos($ui->get_permissions($ou, $acl), 'r') !== FALSE) && ($filter == '')) {
       return objects::count($type, $ou, $filter, TRUE);
     } else {
       return count(objects::ls($type, NULL, $ou, $filter, TRUE));