[FIX]Fixed the issue of technical name of the report while downloading, ...

...set the filename as name field of the report object instad of the reportname field

Task: https://www.odoo.com/web#id=10870&view_type=form&model=project.task&action=327
Pad: https://pad.odoo.com/p/r.CZoUazJ2p928ZBnf