Also exclude template pages that are non-terminal

See https://github.com/xwiki/xwiki-platform/blob/e3c47745195fb445b054537be86f5c01ee69558b/xwiki-platform-core/xwiki-platform-livetable/xwiki-platform-livetable-ui/src/main/resources/XWiki/LiveTableResultsMacros.xml#L214-L218

Right now this doesn't work if your template page is non-terminal. The code probably pre-dates the introduction of nested pages. Note that nested templates is a feature so we need to support that use case.