Stop creating jeepyb scratch repos

A long time ago, we created repos on the git farm for the use of
Zuul.  We put those in /var/lib/git/zuul.  They were not added
to the cgit index, so were generally not visible.

E.g., /var/lib/git/zuul/openstack/nova.git

We no longer use them, and we now want to create repos in the
zuul namespace, E.g., /var/lib/git/zuul/project-config.git.

Therefore we need to tell jeepyb to stop creating repos in the
zuul directory and additionally manually remove the repos from
the git servers.

Change-Id: Ibb72bc5e8a21195e829f55c5bea242ca69c6fceb

modules/openstack_project/manifests/git_backend.pp

@@ -197,11 +197,6 @@ class openstack_project::git_backend (
   exec { 'create_cgitrepos':
     command     => 'create-cgitrepos',
     path        => '/bin:/usr/bin:/usr/local/bin',
-    environment => [
-      'SCRATCH_SUBPATH=zuul',
-      'SCRATCH_OWNER=zuul',
-      'SCRATCH_GROUP=zuul',
-    ],
     require     => [
       File['/home/cgit/projects.yaml'],
       User['zuul'],