disable more useful msg in disk i/o error case
disable more useful msg in disk i/o error case

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