day19.md edited online with Bitbucket, fixed the ListObj error

--HG--
branch : Sorunome/day19md-edited-online-with-bitbucket-fix-1419196561226
Merged in Sorunome/83pa28d/Sorunome/day19md-edited-online-with-bitbucket-fix-1419196561226 (pull request #4)

day19.md edited online with Bitbucket, fixed the ListObj error