and fix a bug in the plugin itself when calling operator's like the one
on std::function<>

Change-Id: I1617607107eeff06785c1841f69e13ad2926218e
Reviewed-on: https://gerrit.libreoffice.org/40446Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>