make the tests work

src/externalldap.js

@@ -491,9 +491,9 @@ function syncGroupUsers(externalLdapConfig, progressCallback, callback) {
         return callback(null, []);
     }
 
-    const getAllGroups = util.callbackify(groups.getAll);
+    const listGroups = util.callbackify(groups.list);
 
-    getAllGroups(function (error, result) {
+    listGroups(function (error, result) {
         if (error) return callback(error);
 
         const ldapGroups = result.filter(function (g) { return g.source === 'ldap'; });