ActiveModel::MissingAttributeError: missing attribute: discussion_id

https://sentry.gitlap.com/gitlab/gitlabcom/issues/10483/

ActiveModel::MissingAttributeError: missing attribute: discussion_id
  app/models/note.rb:268:in `ensure_discussion_id'
    return if self.discussion_id
  lib/gitlab/metrics/instrumentation.rb:155:in `block in ensure_discussion_id'
    trans.method_call_for(#{label.to_sym.inspect}).measure { super }
  lib/gitlab/metrics/method_call.rb:23:in `measure'
    retval = yield
  lib/gitlab/metrics/instrumentation.rb:155:in `ensure_discussion_id'
    trans.method_call_for(#{label.to_sym.inspect}).measure { super }
  app/models/network/graph.rb:31:in `collect_notes'
    .each do |item|
...
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