fix upgrading of latex references
fix upgrading of latex references

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