Use correct class path for token persistence backend

Keystone has moved over to using a new location for the token
persistence backends (drivers). The old values will continue to
work, but this will limit the deprecation warnings for an out
of the box devstack install.

Change-Id: I7c437788c8aee0106fa7f3c37617fbd1220291ef
bp: non-persistent-tokens
diff --git a/lib/keystone b/lib/keystone
index c6e17ca..a3e7267 100644
--- a/lib/keystone
+++ b/lib/keystone
@@ -229,11 +229,11 @@
     iniset $KEYSTONE_CONF ec2 driver "keystone.contrib.ec2.backends.sql.Ec2"
 
     if [[ "$KEYSTONE_TOKEN_BACKEND" = "sql" ]]; then
-        iniset $KEYSTONE_CONF token driver keystone.token.backends.sql.Token
+        iniset $KEYSTONE_CONF token driver keystone.token.persistence.backends.sql.Token
     elif [[ "$KEYSTONE_TOKEN_BACKEND" = "memcache" ]]; then
-        iniset $KEYSTONE_CONF token driver keystone.token.backends.memcache.Token
+        iniset $KEYSTONE_CONF token driver keystone.token.persistence.backends.memcache.Token
     else
-        iniset $KEYSTONE_CONF token driver keystone.token.backends.kvs.Token
+        iniset $KEYSTONE_CONF token driver keystone.token.persistence.backends.kvs.Token
     fi
 
     if [[ "$KEYSTONE_CATALOG_BACKEND" = "sql" ]]; then