Config driver: use "True" instead of "always"

Commit c12a78b35dc910fa97df888960ef2b9a64557254 has set the
"always" flag to be deprecated in liberty. This moves to using
"True" instead.

Change-Id: Idecf7966968369d2f372abffcab85fbf9aa097c7

lib/nova

@@ -81,7 +81,7 @@ NOVA_ROOTWRAP=$(get_rootwrap_location nova)
 
 # Option to enable/disable config drive
 # NOTE: Set FORCE_CONFIG_DRIVE="False" to turn OFF config drive
-FORCE_CONFIG_DRIVE=${FORCE_CONFIG_DRIVE:-"always"}
+FORCE_CONFIG_DRIVE=${FORCE_CONFIG_DRIVE:-"True"}
 
 # Nova supports pluggable schedulers.  The default ``FilterScheduler``
 # should work in most cases.