[DOC] Fix default value of shift_age [ci skip]
LogDevice#initialize treats shift_age: nil as 7, but Logger#initialize has the default value of shift_age as 0.
LogDevice#initialize
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56328 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
[DOC] Fix default value of shift_age [ci skip]
LogDevice#initialize
treats shift_age: nil as 7, butLogger#initialize has the default value of shift_age as 0.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56328 b2dd03c8-39d4-4d8f-98ff-823fe69b080e