move r12689 awesome_nested_set modification to config/initializers/10-patches.rb (#7920)

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extra : convert_revision : svn%3Ae93f8b46-1217-0410-a6f0-8f06a7374b81/trunk%4012733
Gemfile: use awesome_nested_set 2.1.6 gem

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extra : convert_revision : svn%3Ae93f8b46-1217-0410-a6f0-8f06a7374b81/trunk%4012734