[hook] use indexer.index_name

hooks.py

@@ -72,7 +72,7 @@
     def postcommit_event(self):
         indexer = self.cnx.vreg['es'].select('indexer', self.cnx)
         es = indexer.get_connection()
-        if es is None or not self.cnx.vreg.config['index-name']:
+        if es is None or not indexer.index_name:
             log.error('no connection to ES (not configured) skip ES indexing')
             return
         for entity in self.get_data():