ignore sticky fields when checking if blank (#843)
ignore sticky fields when checking if blank (#843)

jakesyl/ruby-card,jakesyl/ruby-card,LucasCabello/anki,subfusc/anki,kenjhim/anki,jkitching/anki,socialpercon/anki-1,weihautin/anki,abeyer/anki,eduOS/anki,florianjacob/anki,hssm/anki,hssm/anki,Stvad/anki,go38/anki,weihautin/anki,xuewenfei/anki,ospalh/libanki3,sunclx/anki,Arthaey/anki,holycrepe/anki