Re-enable the zuul config check

This was temporarily disabled for a one-time import.

Change-Id: Ic719b9053c4de025543c2f038aa3d01c70cd5fb5

gerrit/projects.yaml

@@ -6782,7 +6782,6 @@
 - project: vexxhost/project-config
   description: Zuul configuration files for the Vexxhost tenant
   acl-config: /home/gerrit2/acls/vexxhost/vexxhost.config
-  upstream: https://opendev.org/opendev/project-config
 - project: vexxhost/rally_exporter
   description: OpenStack Rally exporter for Prometheus
   acl-config: /home/gerrit2/acls/vexxhost/vexxhost.config

tools/check_valid_gerrit_projects.py

@@ -79,8 +79,7 @@ def check_repo(repo_path, default_branch):
             head = repo.head.commit.tree
             for z in ['zuul.yaml', '.zuul.yaml', 'zuul.d', '.zuul.d']:
                 if z in head:
-                    # TEMPORARY:
-                    # found_errors += 1
+                    found_errors += 1
                     print("  ERROR: Found %s on branch %s" % (z, branch))
                     print("    Remove any zuul config files before import.")