Remove release-openstack-server

This template needs to stay in project-config to work properly.
also, it's obsolete. project-config is updated already.

Change-Id: I818b10cd6614870fc0673d96d20a9fe66b99ba94

zuul.d/layout.yaml

@@ -1,7 +1,6 @@
 - project:
     templates:
       - tripleo-multinode-container-minimal
-      - release-openstack-server
     check:
       jobs:
         - openstack-tox-linters