minor(reader.lua): remove unnecessary import
minor(reader.lua): remove unnecessary import

NiLuJe/koreader,mihailim/koreader,frankyifei/koreader,Frenzie/koreader,robert00s/koreader,poire-z/koreader,Markismus/koreader,Frenzie/koreader,lgeek/koreader,Hzj-jie/koreader,apletnev/koreader,pazos/koreader,NickSavage/koreader,poire-z/koreader,chihyang/koreader,koreader/koreader,mwoz123/koreader,houqp/koreader,koreader/koreader,NiLuJe/koreader