prepare DB for #4482


git-svn-id: https://forge.indepnet.net/svn/glpi/trunk@22267 35612d4c-9d10-0410-837c-bf9dd1be60d7
Add date limit for KnowbaseItem fixed #4482
fix display for #4227


git-svn-id: https://forge.indepnet.net/svn/glpi/trunk@22268 35612d4c-9d10-0410-837c-bf9dd1be60d7