FN_DELETE_TEXT_FORMFIELDS is only handled in SwTextShell::ExecField()
and SwTextShell::StateField() doesn't seem to have a default handler for
slots not mentioned explicitly, so this is not needed.
Change-Id: I00bc3c543c44d541d352748c721be43b76965e32
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/146144
Tested-by: Jenkins
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>