compilerplugins: Fix tutorials plugins

Broken in commit 1f078fcaddd45bb074e4d0a4933db01f6e8b623e

Change-Id: Ica93c3b9309b2ae4d973ccc34a84b5accac7472c
Reviewed-on: https://gerrit.libreoffice.org/10478
Reviewed-by: Thomas Arnhold <thomas@arnhold.org>
Tested-by: Thomas Arnhold <thomas@arnhold.org>