merge revision(s) 57809: [Backport #13291]
fix paren * string.c (str_byte_substr): fix misplaced parenthesis at r56155.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@57937 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 57809: [Backport #13291]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@57937 b2dd03c8-39d4-4d8f-98ff-823fe69b080e