Projects without import_url cannot be mirrors

CHANGELOG-EE

@@ -8,6 +8,7 @@ v 8.9.0 (unreleased)
   - Add API endpoint for Merge Request Approvals !449
   - Distribute RepositoryUpdateMirror jobs in time and add exclusive lease on them by project_id
   - [Elastic] Move ES settings to application settings
+  - Disable mirror flag for projects without import_url
 
 v 8.8.5
   - Make sure OAuth routes that we generate for Geo matches with the ones in Rails routes !444

db/migrate/20160615092001_disable_mirror_without_import_url.rb

+# RemoveWrongImportUrlFromProjects migration missed setting the mirror flag to false when making import_url nil
+# for invalid URIs that why we need this migration.
+
+class DisableMirrorWithoutImportUrl < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  def up
+    execute("UPDATE projects SET mirror = false WHERE projects.mirror = true AND (projects.import_url IS NULL OR projects.import_url = '')")
+  end
+end