[xwiki-users] Syntax 1.0 is not shown as syntax option

I've changed XWiki 5.1 configuration file .../xwiki/WEB-INF/xwiki.cfg line to the: ... xwiki.rendering.syntaxes = xwiki/1.0, xwiki/2.0, xwiki/2.1 ... but Document Syntax combo box still shows only XWiki 2.1 XWiki 2.0 as possible options. Where could be the catch? Valdis