change to backed keystone by default

Change-Id: Ibfce8d1558eb7d43cc39d6397d8714cf8ccd335b
Signed-off-by: tierno <alfonso.tiernosepulveda@telefonica.com>
diff --git a/osm_nbi/nbi.cfg b/osm_nbi/nbi.cfg
index f97b078..d279f90 100644
--- a/osm_nbi/nbi.cfg
+++ b/osm_nbi/nbi.cfg
@@ -91,7 +91,7 @@
 group_id: "nbi-server"
 
 [authentication]
-backend: "internal"         # internal or keystone
+backend: "keystone"         # internal or keystone
 # for keystone backend a comma separated list of user adn project _domain_name list can ba provided.
 # NBI will try authenticate with all of then if domain is not provided in the content of a POST token
 # user_domain_name:         "default,ldap"