Keystone re-enable catalog caching

Catalog caching was disabled due to bug 1537617, but this has been
fixed for some time. Re-enabling to get some performance back.

Change-Id: Ic0edf5c70a5040edf3393dbd1e110ab5fb56c110
Related-Bug: 1537617
diff --git a/lib/keystone b/lib/keystone
index 6198e43..f8119eb 100644
--- a/lib/keystone
+++ b/lib/keystone
@@ -248,9 +248,6 @@
     iniset $KEYSTONE_CONF cache backend "oslo_cache.memcache_pool"
     iniset $KEYSTONE_CONF cache memcache_servers localhost:11211
 
-    # Do not cache the catalog backend due to https://bugs.launchpad.net/keystone/+bug/1537617
-    iniset $KEYSTONE_CONF catalog caching "False"
-
     iniset_rpc_backend keystone $KEYSTONE_CONF
 
     # Register SSL certificates if provided