Ci::CreatePipelineService::CreateError: Insufficient permissions for protected ref 'master'

https://sentry.gitlab.net/gitlab/gitlabcom/issues/587398/

Ci::CreatePipelineService::CreateError: Insufficient permissions for protected ref 'master'
  ci/create_pipeline_service.rb:64:in `block in execute!'
    raise CreateError, pipeline.errors.full_messages.join(',')
  ci/create_pipeline_service.rb:62:in `tap'
    execute(*args, &block).tap do |pipeline|
  ci/create_pipeline_service.rb:62:in `execute!'
    execute(*args, &block).tap do |pipeline|
  pipeline_schedule_worker.rb:15:in `block in perform'
    .execute!(:schedule, ignore_skip_ci: true, save_on_errors: true, schedule: schedule)
  active_record/relation/batches.rb:59:in `block (2 levels) in find_each'
    records.each { |record| yield record }
...
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Ci::CreatePipelineService::CreateError: Insufficient permissions for protected ref 'master'