NoMethodError: undefined method `term_agreements' for nil:NilClass

https://sentry.gitlab.net/gitlab/gitlabcom/issues/1242497/

NoMethodError: undefined method `term_agreements' for nil:NilClass
  users/respond_to_terms_service.rb:11:in `execute'
    agreement = @user.term_agreements.find_or_initialize_by(term: @term)
  gitlab/metrics/instrumentation.rb:161:in `block in execute'
    .measure { super }
  gitlab/metrics/method_call.rb:36:in `measure'
    retval = yield
  gitlab/metrics/instrumentation.rb:161:in `execute'
    .measure { super }
  users/terms_controller.rb:27:in `accept'
    .execute(accepted: true)
...
(133 additional frame(s) were not displayed)

NoMethodError: undefined method `term_agreements' for nil:NilClass