no need to explicit delete SvtScriptedTextHelper_Impl assinment operator
because it's implicit deleted anyway.

Change-Id: I8463345e9035fc0466a22ed6648eb5b2614ed1b5
Reviewed-on: https://gerrit.libreoffice.org/44927Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>