json/add/range.rb: use Range#end
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42404 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
json/add/range.rb: use Range#end
instead of Range#last which can be affected by Range#exclusive?.
ref [Bug #8739]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42404 b2dd03c8-39d4-4d8f-98ff-823fe69b080e