merge revision(s) 62422: [Backport #14481]
Merge RubyGems 2.7.6 from upstream. It fixed some security vulnerabilities. http://blog.rubygems.org/2018/02/15/2.7.6-released.html
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@62434 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 62422: [Backport #14481]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@62434 b2dd03c8-39d4-4d8f-98ff-823fe69b080e