merge revision(s) 67247: [Backport #15666]
Guard out the test when it is run under root permission
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_5@67704 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 67247: [Backport #15666]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_5@67704 b2dd03c8-39d4-4d8f-98ff-823fe69b080e