use lambda form in acts_as_tree scope (#12499)

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extra : convert_revision : svn%3Ae93f8b46-1217-0410-a6f0-8f06a7374b81/trunk%4012487
Rails4: replace deprecated Relation#update_all at db migrations

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extra : convert_revision : svn%3Ae93f8b46-1217-0410-a6f0-8f06a7374b81/trunk%4012488