update Rails version 3.2.16

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extra : convert_revision : svn%3Ae93f8b46-1217-0410-a6f0-8f06a7374b81/trunk%4012355
remove trailing white-spaces from test/unit/attachment_test.rb

--HG--
extra : convert_revision : svn%3Ae93f8b46-1217-0410-a6f0-8f06a7374b81/trunk%4012356