[ruby-cvs:78597] 7a1c56f978 (master): [ruby/logger] Document that shift_age of 0 disables log file rotation

Jeremy Evans	2019-11-18 10:34:56 +0900 (Mon, 18 Nov 2019)

  New Revision: 7a1c56f978

  https://github.com/ruby/ruby/commit/7a1c56f978

  Log:
    [ruby/logger] Document that shift_age of 0 disables log file rotation
    
    Fixes Ruby Bug 16349.
    
    https://github.com/ruby/logger/commit/b1b6d06f2d

  Modified files:
    lib/logger.rb