authentic: do not send provisionning messages to empty audience (#20309)

hobo/agent/authentic2/provisionning.py

@@ -147,6 +147,8 @@ class Provisionning(object):
             else:
                 for ou, users in ous.iteritems():
                     audience = [a for service, a in self.get_audience(ou)]
+                    if not audience:
+                        continue
                     self.logger.info(u'provisionning users %s to %s',
                                      u', '.join(map(unicode, users)), u', '.join(audience))
                     notify_agents({