updated spec

spec/lib/gitlab/import_export/project_tree_restorer_spec.rb

@@ -190,8 +190,8 @@ describe Gitlab::ImportExport::ProjectTreeRestorer, services: true do
         end
       end
 
-      context 'existing builds' do
-        it 'do not throw errors' do
+      context 'when there is an existing build with build token' do
+        it 'restores project json correctly' do
           create(:ci_build, token: 'abcd')
 
           expect(restored_project_json).to be true