Fix typo in typed trigger validation

[alex01t]

This fixes annoying warning in type = :command triggers:

==> b-1: The command 'provision' was not found for this trigger. ==> b-1: The command 'provision' was not found for this trigger. ..

  config.trigger.after :provision, type: :command do |t|
    t.name = "finally run real provision over all boxes"
    t.run = { inline: "bash -ex -c '
       id
     '"}
  end

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