Fixed changes in motion poll serializer.
Fixed changes in motion poll serializer.

jwinzer/OpenSlides,rolandgeider/OpenSlides,jwinzer/OpenSlides,normanjaeckel/OpenSlides,rolandgeider/OpenSlides,OpenSlides/OpenSlides,jwinzer/OpenSlides,boehlke/OpenSlides,emanuelschuetze/OpenSlides,ostcar/OpenSlides,FinnStutzenstein/OpenSlides,ostcar/OpenSlides,CatoTH/OpenSlides,OpenSlides/OpenSlides,FinnStutzenstein/OpenSlides,tsiegleauq/OpenSlides,boehlke/OpenSlides,CatoTH/OpenSlides,normanjaeckel/OpenSlides,tsiegleauq/OpenSlides,rolandgeider/OpenSlides,boehlke/OpenSlides,CatoTH/OpenSlides,FinnStutzenstein/OpenSlides,jwinzer/OpenSlides,FinnStutzenstein/OpenSlides,normanjaeckel/OpenSlides,emanuelschuetze/OpenSlides,tsiegleauq/OpenSlides,ostcar/OpenSlides,emanuelschuetze/OpenSlides,CatoTH/OpenSlides,normanjaeckel/OpenSlides,boehlke/OpenSlides,emanuelschuetze/OpenSlides,jwinzer/OpenSlides