fix rake migration task from ignoring Upload(store: nil)

lib/tasks/gitlab/uploads/migrate.rake

@@ -25,8 +25,8 @@ namespace :gitlab do
       Upload.class_eval { include EachBatch } unless Upload < EachBatch
 
       Upload
-        .where.not(store: @to_store)
-        .where(uploader: @uploader_class.to_s,
+        .where(store: [nil, 1],
+               uploader: @uploader_class.to_s,
                model_type: @model_class.base_class.sti_name)
     end
   end

spec/tasks/gitlab/uploads/migrate_rake_spec.rb

@@ -20,9 +20,20 @@ describe 'gitlab:uploads:migrate rake tasks' do
     run_rake_task("gitlab:uploads:migrate", *args)
   end
 
-  it 'enqueue jobs in batch' do
-    expect(ObjectStorage::MigrateUploadsWorker).to receive(:enqueue!).exactly(4).times
+  shared_examples 'enqueue jobs in batch' do |batch:|
+    it do
+      expect(ObjectStorage::MigrateUploadsWorker)
+        .to receive(:enqueue!).exactly(batch).times
 
       run
     end
+  end
+
+  context 'Upload has store = nil' do
+    before do
+      Upload.where(model: projects.first(5)).update_all(store: nil)
+    end
+
+    it_behaves_like 'enqueue jobs in batch', batch: 4
+  end
 end