Fix typo in notification index template

Change-Id: If405274c1ce97f1446247622278cc86780362f5d
diff --git a/elasticsearch/files/es_template_notification.json b/elasticsearch/files/es_template_notification.json
index 6754ffd..be645d5 100644
--- a/elasticsearch/files/es_template_notification.json
+++ b/elasticsearch/files/es_template_notification.json
@@ -62,8 +62,8 @@
                     "format": "dateOptionalTime"
                 },
                 "publisher": {
-                    "type": "not_analyzed",
-                    "format": "string"
+                    "index": "not_analyzed",
+                    "type": "string"
                 }
             }
         }