prevent invalid OOXML files with trendlines, related #i88825#

Change-Id: I503b24233060400cf4bbb40701bec0a3e101512a
Reviewed-on: https://gerrit.libreoffice.org/8095
Reviewed-by: Kohei Yoshida <libreoffice@kohei.us>
Tested-by: Kohei Yoshida <libreoffice@kohei.us>