Don't inherit Octavia-specific gtw class from openstack_gateway_*

Classes openstack_gateway_single_octavia and
openstack_gateway_cluster_octavia had a single purpose:
add system.octavia.metadata.single role to one of the gateway nodes.

Inheriting them from openstack_gateway_* made the class import order
strict, meaning that parameters from service.octavia.metadata.single
would always override those defined in cluster.${_param:cluster_name}.openstack.gateway
class and those that inherit from it. This is not a desired situation.

To allow controlling the order in which classes are included, removed
inheritance inside openstack_gateway_single_octavia class and deleted
openstack_gateway_cluster_octavia as it now duplicates the former.

Change-Id: Ia26d1e31f6c9a57131d77a4c6d1369069e513a9e
diff --git a/reclass/storage/system/openstack_gateway_cluster_octavia.yml b/reclass/storage/system/openstack_gateway_cluster_octavia.yml
deleted file mode 100644
index 8126ed1..0000000
--- a/reclass/storage/system/openstack_gateway_cluster_octavia.yml
+++ /dev/null
@@ -1,9 +0,0 @@
-classes:
-- system.reclass.storage.system.openstack_gateway_cluster
-parameters:
-  reclass:
-    storage:
-      node:
-        openstack_gateway_node01:
-          classes:
-          - system.octavia.manager.single
diff --git a/reclass/storage/system/openstack_gateway_single_octavia.yml b/reclass/storage/system/openstack_gateway_single_octavia.yml
index f43e6a1..264b3f1 100644
--- a/reclass/storage/system/openstack_gateway_single_octavia.yml
+++ b/reclass/storage/system/openstack_gateway_single_octavia.yml
@@ -1,5 +1,3 @@
-classes:
-- system.reclass.storage.system.openstack_gateway_single
 parameters:
   reclass:
     storage: