Set default 'ou' name for LDAP projects to Projects

The default ou name for projects/tenants should be Projects, as we normally
use in devstack and ldap live test. Since multiple LDAP objects can
use groupOfNames, setting projects group to Groups is vague.

Fixes Bug1191807

Change-Id: I1718c76320da51a58abf6558a9b8560e908773cb
Merge "Set default 'ou' name for LDAP projects to Projects"